Chemistry of life (Biochemistry)
The study of chemical compounds that are vital for living organisms to sustain life is called biochemistry. The subject deals with the nature of these compounds and characteristic reactions they make inside the living organisms . We are not involved fundamentally with the study of biochemistry as a subject , but to give brief introduction to main classes of the organic compounds in this important field. It is beyond this discussion to present detailed explanation of these essential organic substances . We will give short introduction of the main classes and their active role in our body . Some of these groups are , carbohydrates , fats and proteins, etc..
· Carbohydrates.
Carbohydrates are classes of organic compounds that consist of carbon , hydrogen and oxygen with an empirical formula of Cm(H2O)n in most cases . The terms m and n can be the same as in the case of C6H12O6 (glucose) or different in the case of C12H22O11 (sucrose) . Another important feature of the carbohydrates is that oxygen and hydrogen are generally in ratio of 2:1 , so that it was historically called hydrates of carbon ; but not all compounds of carbohydrates necessarily maintain this hydrogen – oxygen ratio and not all compounds that fit this hydrogen-oxygen ratio are carbohydrates .
In biochemistry the term carbohydrate denotes different compounds called saccharides . These compounds include sugars , starch and cellulose . Saccharides (Greek word meaning sugars) are generally classified into monosaccharides , disaccharides and polysaccharides .
Monosaccharides are the simple sugars which are either aldoses (aldehydes) like glucose or ketoses ( ketones) like fructose . These simple sugars are further classified on the base of the number of carbon atoms they contain like pentose (containing five carbon atoms) , or hexose (containing six carbon atoms) .
Carbohydrates are naturally formed in a process called photosynthesis in which plants combine CO2 from the air and water from the soil in the presence of chlorophyll , sunlight and certain enzymes producing simple sugars .
6 CO2 + 6H2O (sun light) C6H12O6 + 6O2
sugar(glucose)
This above reaction is not simple process as it looks , but extremely complicated reaction with different intermediate steps before it gives the final product . since the final product is a monosaccharide , plants have the ability to synthesize disaccharides by combining two molecules of monosaccharides .
2 C6H12O6 C12H1.
Introduction to Carbohydrates and its ChemistryDHANANJAY PATIL
A Comprehensive Introduction to Carbohydrates its chemistry, classification, qualitative tests an disorders related to its metabolism. This will give readers a overall insight to this topic. All types of queries and suggestions are most welcome
This presentation is based on the main topics dealing with chapter no 14.of chemistry.this chapter deals with the introduction ,classification,properties and functions of carbohydrates,proteins, Enzymes,vitamins,nucleic acids,lipid etc. this presentation will help students as well as teachers in the teaching learning process
Introduction to Carbohydrates and its ChemistryDHANANJAY PATIL
A Comprehensive Introduction to Carbohydrates its chemistry, classification, qualitative tests an disorders related to its metabolism. This will give readers a overall insight to this topic. All types of queries and suggestions are most welcome
This presentation is based on the main topics dealing with chapter no 14.of chemistry.this chapter deals with the introduction ,classification,properties and functions of carbohydrates,proteins, Enzymes,vitamins,nucleic acids,lipid etc. this presentation will help students as well as teachers in the teaching learning process
Lec 1 Carbohydrates-1.pptx the signs and symptoms of Kwashiorkor and Marasmus...phatimamohamett054
For security reasons why you think some students do the signs and symptoms of Kwashiorkor disease ppt biochemistry and Marasmus and Marasmus and Marasmus and Marasmus and Marasmus and Marasmus and the children are the signs of all that would have small mouth
Ncert biomolecules you can read and enjoy very beneficial for competitive exams klkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkeoksnbwjrkieowlsniqoqkueiorkeusiknej3irognnruigkfnr4hhgkgoifdnh3urowkjsqildjhdowndhufnfehejksndksjtoeosjsnqhskdueubayjsnwhjendnsnshdjmsjhidknsnssnsjsks
Chemistry of Life Biological MoleculesBiological Molecules.docxbissacr
Chemistry of Life: Biological Molecules
Biological Molecules
By the end of this section, you will be able to:
· describe the ways in which carbon is critical to life
· explain the impact of slight changes in amino acids on organisms
· describe the four major types of biological molecules
· understand the functions of the four major types of molecules.
The large molecules necessary for life that are built from smaller organic molecules are called biological macromolecules. There are four major classes of biological macromolecules (carbohydrates, lipids, proteins, and nucleic acids), and each is an important component of the cell and performs a wide array of functions. Combined, these molecules make up the majority of a cell's mass. Biological macromolecules are organic, meaning that they contain carbon. In addition, they may contain hydrogen, oxygen, nitrogen, phosphorus, sulfur, and additional minor elements.
Carbon
It is often said that life is "carbon-based." This means that carbon atoms, bonded to other carbon atoms or other elements, form the fundamental components of many, if not most, of the molecules found uniquely in living things. Other elements play important roles in biological molecules, but carbon certainly qualifies as the "foundation" element for molecules in living things. It is the bonding properties of carbon atoms that are responsible for its important role.
Carbon Bonding
Carbon contains four electrons in its outer shell. Therefore, it can form four covalent bonds with other atoms or molecules. The simplest organic carbon molecule is methane (CH4), in which four hydrogen atoms bind to a carbon atom (Figure 13).
Figure 13: Molecular Structure of Methane
Carbon can form four covalent bonds to create an organic molecule. The simplest carbon molecule is methane (CH4), depicted here.
OpenStax
However, structures that are more complex are made using carbon. Any of the hydrogen atoms could be replaced with another carbon atom covalently bonded to the first carbon atom. In this way, long and branching chains of carbon compounds can be made (Figure 14a). The carbon atoms may bond with atoms of other elements, such as nitrogen, oxygen, and phosphorus (Figure 14b). The molecules may also form rings, which themselves can link with other rings (Figure 14c). This diversity of molecular forms accounts for the diversity of functions of the biological macromolecules and is based to a large degree on the ability of carbon to form multiple bonds with itself and other atoms.
Figure 14: Molecular Structure of Stearic Acid, Glycine, and Glucose
These examples show three molecules (found in living organisms) that contain carbon atoms bonded in various ways to other carbon atoms and the atoms of other elements. (a) This molecule of stearic acid has a long chain of carbon atoms. (b) Glycine, a component of proteins, contains carbon, nitrogen, oxygen, and hydrogen atoms. (c) Glucose, a sugar, has a ring of carbon atoms and one oxygen atom.
OpenSt.
Biochemistry of Carbohydrates for MBBS, BDS, Lab Med 2024.pptxRajendra Dev Bhatt
Carbohydrates are carbon compounds that contain large quantities of hydroxyl groups.
The simplest carbohydrates also contain either an aldehyde moiety (these are termed polyhydroxyaldehydes) or a ketone moiety (polyhydroxyketones).
All carbohydrates can be classified as either monosaccharides, oligosaccharides or polysaccharides.
Choose 1 focal point from each subcategory of practice, educatio.docxbissacr
Choose 1 focal point from each subcategory of practice, education, research and administration and describe how the APRN can provide effective care in end of life management
Using the American nurses association position statement, recommendations for improvement in end of life management focuses on practice, education, research and administration. Listed below are steps that nurses can take to overcome barriers in healthcare practice.
Practice
1. Strive to attain a standard of primary palliative care so that all health care providers have basic knowledge of palliative nursing to improve the care of patients and families.
2. All nurses will have basic skills in recognizing and managing symptoms, including pain, dyspnea, nausea, constipation, and others.
3. Nurses will be comfortable having discussions about death, and will collaborate with the care teams to ensure that patients and families have current and accurate information about the possibility or probability of a patient’s impending death.
4. Encourage patient and family participation in health care decision-making, including the use of advance directives in which both patient preferences and surrogates are identified.
Education
1. Those who practice in secondary or tertiary palliative care will have specialist education and certification.
2. Institutions and schools of nursing will integrate precepts of primary palliative care into curricula.
3. Basic and specialist End-of-Life Nursing Education Consortium (ELNEC) resources will be available.
4. Advocate for additional education in academic programs and work settings related to palliative care, including symptom management, supported decision-making, and end-of-life care, focusing on patients and families.
Research
1. Increase the integration of evidence-based care across the dimensions of end-of-life care.
2. Develop best practices for quality care across the dimensions of end-of-life care, including the physical, psychological, spiritual, and interpersonal.
3. Support the use of evidence-based and ethical care, and support decision-making for care at the end of life.
4. Develop best practices to measure the quality and effectiveness of the counseling and interdisciplinary care patients and families receive regarding end-of-life decision-making and treatments.
5. Support research that examines the relationship of patient and family satisfaction and their utilization of health care resources in end-of-life care choices.
Administration
1. Promote work environments in which the standards for excellent care extend through the patient’s death and into post-death care for families.
2. Encourage facilities and institutions to support the clinical competence and professional development that will help nurses provide excellent, dignified, and compassionate end-of-life care.
3. Work toward a standard of palliative care available to patients and families from the time of diagnosis of a serious illness or a.
CHOICE TOPIC Pick a philosophical topic of your own choosing and re.docxbissacr
CHOICE TOPIC: Pick a philosophical topic of your own choosing and relay your own perspective on that topic giving as much evidence and supporting reasoning as possible.
The assignment should be standard font, double spaced, at least a page and a half with proper citations when appropriate.
.
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Lec 1 Carbohydrates-1.pptx the signs and symptoms of Kwashiorkor and Marasmus...phatimamohamett054
For security reasons why you think some students do the signs and symptoms of Kwashiorkor disease ppt biochemistry and Marasmus and Marasmus and Marasmus and Marasmus and Marasmus and Marasmus and the children are the signs of all that would have small mouth
Ncert biomolecules you can read and enjoy very beneficial for competitive exams klkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkeoksnbwjrkieowlsniqoqkueiorkeusiknej3irognnruigkfnr4hhgkgoifdnh3urowkjsqildjhdowndhufnfehejksndksjtoeosjsnqhskdueubayjsnwhjendnsnshdjmsjhidknsnssnsjsks
Chemistry of Life Biological MoleculesBiological Molecules.docxbissacr
Chemistry of Life: Biological Molecules
Biological Molecules
By the end of this section, you will be able to:
· describe the ways in which carbon is critical to life
· explain the impact of slight changes in amino acids on organisms
· describe the four major types of biological molecules
· understand the functions of the four major types of molecules.
The large molecules necessary for life that are built from smaller organic molecules are called biological macromolecules. There are four major classes of biological macromolecules (carbohydrates, lipids, proteins, and nucleic acids), and each is an important component of the cell and performs a wide array of functions. Combined, these molecules make up the majority of a cell's mass. Biological macromolecules are organic, meaning that they contain carbon. In addition, they may contain hydrogen, oxygen, nitrogen, phosphorus, sulfur, and additional minor elements.
Carbon
It is often said that life is "carbon-based." This means that carbon atoms, bonded to other carbon atoms or other elements, form the fundamental components of many, if not most, of the molecules found uniquely in living things. Other elements play important roles in biological molecules, but carbon certainly qualifies as the "foundation" element for molecules in living things. It is the bonding properties of carbon atoms that are responsible for its important role.
Carbon Bonding
Carbon contains four electrons in its outer shell. Therefore, it can form four covalent bonds with other atoms or molecules. The simplest organic carbon molecule is methane (CH4), in which four hydrogen atoms bind to a carbon atom (Figure 13).
Figure 13: Molecular Structure of Methane
Carbon can form four covalent bonds to create an organic molecule. The simplest carbon molecule is methane (CH4), depicted here.
OpenStax
However, structures that are more complex are made using carbon. Any of the hydrogen atoms could be replaced with another carbon atom covalently bonded to the first carbon atom. In this way, long and branching chains of carbon compounds can be made (Figure 14a). The carbon atoms may bond with atoms of other elements, such as nitrogen, oxygen, and phosphorus (Figure 14b). The molecules may also form rings, which themselves can link with other rings (Figure 14c). This diversity of molecular forms accounts for the diversity of functions of the biological macromolecules and is based to a large degree on the ability of carbon to form multiple bonds with itself and other atoms.
Figure 14: Molecular Structure of Stearic Acid, Glycine, and Glucose
These examples show three molecules (found in living organisms) that contain carbon atoms bonded in various ways to other carbon atoms and the atoms of other elements. (a) This molecule of stearic acid has a long chain of carbon atoms. (b) Glycine, a component of proteins, contains carbon, nitrogen, oxygen, and hydrogen atoms. (c) Glucose, a sugar, has a ring of carbon atoms and one oxygen atom.
OpenSt.
Biochemistry of Carbohydrates for MBBS, BDS, Lab Med 2024.pptxRajendra Dev Bhatt
Carbohydrates are carbon compounds that contain large quantities of hydroxyl groups.
The simplest carbohydrates also contain either an aldehyde moiety (these are termed polyhydroxyaldehydes) or a ketone moiety (polyhydroxyketones).
All carbohydrates can be classified as either monosaccharides, oligosaccharides or polysaccharides.
Choose 1 focal point from each subcategory of practice, educatio.docxbissacr
Choose 1 focal point from each subcategory of practice, education, research and administration and describe how the APRN can provide effective care in end of life management
Using the American nurses association position statement, recommendations for improvement in end of life management focuses on practice, education, research and administration. Listed below are steps that nurses can take to overcome barriers in healthcare practice.
Practice
1. Strive to attain a standard of primary palliative care so that all health care providers have basic knowledge of palliative nursing to improve the care of patients and families.
2. All nurses will have basic skills in recognizing and managing symptoms, including pain, dyspnea, nausea, constipation, and others.
3. Nurses will be comfortable having discussions about death, and will collaborate with the care teams to ensure that patients and families have current and accurate information about the possibility or probability of a patient’s impending death.
4. Encourage patient and family participation in health care decision-making, including the use of advance directives in which both patient preferences and surrogates are identified.
Education
1. Those who practice in secondary or tertiary palliative care will have specialist education and certification.
2. Institutions and schools of nursing will integrate precepts of primary palliative care into curricula.
3. Basic and specialist End-of-Life Nursing Education Consortium (ELNEC) resources will be available.
4. Advocate for additional education in academic programs and work settings related to palliative care, including symptom management, supported decision-making, and end-of-life care, focusing on patients and families.
Research
1. Increase the integration of evidence-based care across the dimensions of end-of-life care.
2. Develop best practices for quality care across the dimensions of end-of-life care, including the physical, psychological, spiritual, and interpersonal.
3. Support the use of evidence-based and ethical care, and support decision-making for care at the end of life.
4. Develop best practices to measure the quality and effectiveness of the counseling and interdisciplinary care patients and families receive regarding end-of-life decision-making and treatments.
5. Support research that examines the relationship of patient and family satisfaction and their utilization of health care resources in end-of-life care choices.
Administration
1. Promote work environments in which the standards for excellent care extend through the patient’s death and into post-death care for families.
2. Encourage facilities and institutions to support the clinical competence and professional development that will help nurses provide excellent, dignified, and compassionate end-of-life care.
3. Work toward a standard of palliative care available to patients and families from the time of diagnosis of a serious illness or a.
CHOICE TOPIC Pick a philosophical topic of your own choosing and re.docxbissacr
CHOICE TOPIC: Pick a philosophical topic of your own choosing and relay your own perspective on that topic giving as much evidence and supporting reasoning as possible.
The assignment should be standard font, double spaced, at least a page and a half with proper citations when appropriate.
.
Choice Hotels InternationalOverviewRead the case study, .docxbissacr
Choice Hotels International
Overview
Read the case study,
Choice Hotels International
.
Instructions
Write a fully developed paper in which you: DO NOT WRITE IN 1ST PERSON
Assess the two distinct networking functions.
Analyze the issues Choice is likely to experience as it expands its network to full global reach. Provide a rationale for your answer.
Critique Choice implementing free high-speed Internet access for all guests in its Clarion Hotels and Comfort Suites from the security point of view.
Use at least three quality resources in this assignment. Note: Wikipedia and similar websites do not qualify as quality resources.
.
Choice Theory- Is to choose to engage in delinquent and criminal beh.docxbissacr
Choice Theory- Is to choose to engage in delinquent and criminal behavior after weighing the consequences and benefits of their actions
Classical Criminology
People have free will to choose criminal or conventional behaviors, people choose to commit crime for reasons of greed or personal need, and crime can be controlled only by the fear of criminal sanctions.
1. In 1764, criminologist Cesare Beccaria wrote An Essay on Crimes and Punishments, which set forth classical criminological theory. He argued that the only justified rationale for laws and punishments was the principle of utility.
2. Beccaria believed the basis of society, as well as the origin of punishments and the right to punish, is the social contract. The only legitimate purpose of punishment is special deterrence and general deterrence.
3. Beccaria believed the best way to prevent and deter crime was to: • Enact laws that are clear, simple, and unbiased, and that reflect the consensus of the population. • Educate the public. • Eliminate corruption from the administration of justice. • Reward virtue.
4. Real-world drawbacks of Beccaria’s theory are: • Not all offenders are alike, juveniles are treated the same as adults. • Similar crimes are not always as similar as they might appear,first-time offenders are treated the same as repeat offenders.
I don't pay for cover pages
1 APA style page
12 pt font
I gave a breakdown of what the teacher is looking for
.
CHM130LLLab 2Measurements Accuracy and PrecisionName __.docxbissacr
CHM130LL
Lab 2
Measurements: Accuracy and Precision
Name : _____________________________
A. Data Tables
Data Table 1 (12 points)
Measurement
Data
(1) Length of aluminum plastic packet
(2) Height of aluminum plastic packet
(3) Temperature of faucet water
(3) Temperature of ice water
(5) Volume of water in 10-mL
graduated cylinder
(6) Volume of water in 50-mL
graduated cylinder
Data Table 2 (10 points)
Measurement
Data
(1) Inside diameter of 50-mL
graduated cylinder
(2) Height of 50-mL graduated cylinder
(3) Water temperature
(4) Initial volume of water in 50-mL
graduated cylinder
10.0 mL
(5) Mass of water in the 50-mL
graduated cylinder
10.0 g
(6) Volume of water and aluminum shot in 50-mL graduated cylinder
(7) Mass of aluminum shot (given on outside of packet)
B. Insert the picture of the plastic packet containing aluminum shots with student’s name and MEID (25 points)
C. Follow-Up Questions (Show all calculations for full credits)
Part I
1. Convert the length and height measurements for the packet that contains the aluminum shot from units of cm to units of mm using the unit-factor method. (10 points)
2. Convert the temperature measurements for the faucet water and the ice water from oC to oF, using the following equation: oF =1.8(oC) + 32. (10 points)
3. Convert the volumes of the water in the 10-mL and 50-mL graduated cylinders from mL to L, using the unit-factor method. (10 points)
4. Looking at your measurements for the volumes of water in the 10-mL and 50-mL graduated cylinders, are your values identical? Discuss at least two reasons why the measurements were not identical. (5 points)
Part II
5. Calculate the volume of the 50mL graduated cylinder using your measurements of diameter and height, using the formula V= πr2h (r=½ diameter). This is your experimental value. (10 points)
6. Assuming the accepted value of the volume of the graduated cylinder is 50.00 mL, calculate the percent error of your volume calculation, using the following formula and the experimental value calculated in question 5: (10 points)
Percent Error
=
|
accepted value - experimental value
accepted value
|
x
100
7. Calculate the mass of 10ml of water in the graduated cylinder using 1/5 the volume calculated in question 5, the density of water of 1.00 g/mL and this given the formula: (10 points)
Density
=
mass
volume
8. Using 10.0 g as the accepted value for the mass of the water, and the mass calculated in #7 above as the experimental value, calculate the percent error of your mass calculation, using the same formula as in #6 above. (10 points)
9. Calculate the volume of aluminum shot added to the graduated cylinder, using the information from Data Table 2 in the following formula: (10 points)
Volume of water and aluminum shot in 50-mL graduated cylinder(#6) – Initial volume of water in 50-mL graduated cylinder (#4) = volume of aluminum shot
10. Calculate the experimental value for density of the aluminum shot based on its mass (given on.
Chocolates by Jacki has provided information relating to its curre.docxbissacr
Chocolates by Jacki has provided information relating to its current year. The Controller has asked you to complete a First-Stage Allocation to Activity Cost Pools. Use the information included in the Excel Simulation and the Excel functions described below to complete the task.
· Cell Reference: Allows you to refer to data from another cell in the worksheet. From the Excel Simulation below, if in a blank cell, “=B7” was entered, the formula would output the result from cell B7, or 400,000 in this example.
· Absolute Reference: Allows you to maintain the original cell reference when a formula is copied to another cell. The cell reference is “locked” by putting a dollar sign ($) before the column and row references. By default a cell reference is relative, so when you copy a formula to another cell the values update based on a relative reference. For example, if you copy the formula “=B8+B9” from cell C1 to cell C2, the formula in cell C2 will relatively update to be “=B9+B10” since the copied formula moved down one cell, the formula cell references also moved down one cell. Conversely, by adding the absolute cell reference “locks” to the equation, the formula will not change when copied to any other cell. For example, “=$B$8+$B$9” written in cell C1 is copied to cell C2, the formula in cell C2 will remain “=$B$8+$B$9”. You can also use a mixed cell reference by only “locking” the column or row only ($B8 or B$8) which locks that specific column or row and the other reference becomes a relative reference and “moves” with the formula as its copied to another cell. For example, if you copy the formula “=B$8+B9” from cell C1 to cell C2, the formula in cell C2 will update to be “=B$8+B10” since the copied formula moved down one cell, the formula cell relative references also moved down one cell, but the absolute “locked” reference remained the same.
· Basic Math functions: Allows you to use the basic math symbols to perform mathematical functions. You can use the following keys: + (plus sign to add), - (minus sign to subtract), * (asterisk sign to multiply), and / (forward slash to divide). From the Excel Simulation below, if in a blank cell “=B18+B19” was entered, the formula would add the values from those cells and output the result, or 250,000 in this example. If using the other math symbols the result would output an appropriate answer for its function.
· SUM function: Allows you to refer to multiple cells and adds all the values. You can add individual cell references or ranges to utilize this function. From the Excel Simulation below, if in a blank cell “=SUM(B13,B14,B15)” was entered, the formula would output the result of adding those three separate cells, or 375,000 in this example. Similarly, if in a blank cell “=SUM(B13:B15)” was entered, the formula would output the same result of adding those cells, except they are expressed as a range in the formula, and the result would be 375,000 in this example.
Quest.
Chloe1a. This study uses qualitative meta-synthesis to take a.docxbissacr
Chloe
1a. This study uses qualitative meta-synthesis to take a holistic approach to innovation in information systems companies. The article stated that the researchers used qualitative meta-synthesis that analyzed over 370 different articles, journals or other written forums, which required a severe amount of time to read a review and correlate to each other to show a holistic approach. Some of the artifacts used were, “Fear of technological complexity”, “Data collection and processing tools”, and others in Table 1 (Lawrence, 2013).
1b. Information systems innovation is difficult. Not only just systems such as Facebook and Google but the backbone of systems that run corporations such as FedEx and UPS. Changing the users’ experience where it is not just easy to use, but functional has always been difficult such as when we think back to how clunky MySpace and AOL were. This article is about how cultures in information systems companies need mediation to generate innovation, which is directly applicable to how to generate innovative environments.
2a. This research focused on how social media could or could not enhance innovation. The researcher’s hypothesis was that a new connection + novel idea = innovation. In order to connect people, the researcher’s used social media due to its proclivity in today’s world. There were 31 owner-managers from the United Kingdom that signed up and 42 interviews that were conducted. The result of those interviews were over 500 pages of transcripts that required combing through, but first as binned by coding into nine different categories. Overall there was an extensive amount of qualitative research conducted is considerably larger than most qualitative studies.
2b. This article specifically applies to my topic of how to generate innovative environments because it takes a 21st-century approach to innovation, which is ironic, and assess how to use social media to generate innovative ideas. Though overall the discovery is that social media is a difficult platform to meet strangers, there is an avenue such as like type communities on social media that would work better.
References:
Lawrence, C. (2013). A Holistic Narrative of Culture’s Mediation of Information Systems Innovation: A
Qualitative Meta-Synthesis. Journal of Global Information Technology Management, 31–52.
Berne, D. F., Coda, R., Krakauer, P., & Donaire, D. (2019). The innovation challenge in micro and small enterprises
(MSE): An exploratory study at São Paulo metropolitan region. Studii de Ştiintă Şi Cultură, 15(4), 235–252. https://doi.org/10.1108/INMR-03-2019-0031
PAUL:
Part one:
Article one: The article chosen discusses how sales professionals perceive leadership. Interviews were conducted with both sales leaders and salespeople. What was found was that the salespeople overwhelmingly supported specific leadership traits that contributed to their overall performance. The four areas covered were coaching, collaborat.
Chinese railroad workers began to contribute to the Canadian railr.docxbissacr
Chinese railroad workers began to contribute to the Canadian railroad in 1800, but they paid a lot of labour and even life with low wages. Now, many bronze men in the Roger's Centre in Toronto are reminding people that many Chinese workers died while building the railroad, they were overworked and their salaries were low (China town concern group, 2016, para.1). However, these hard and lovely people have not received the respect they deserve in such a difficult situation. After they built the Canadian Pacific Railway, one of Canada's outstanding engineering projects, they were discriminatorily levied a head tax on Chinese workers. As the Frey (2017) suggests, the racist law imposed a "head tax" on Chinese immigrants from 1885 to 1923, acknowledging that the abuse of Chinese immigrants is a long process, and it is necessary to fight against historical inertia and racist laws (para.18). Over time, people's awareness of racism has increased, and they have begun to reflect on previous mistakes and modify some wrong regulations and measures. The websites show the unequal treatment and compensation of many Chinese railroad workers.
Reference
China town concern group. (2016, April 28). “Now and Then: Chinese Railroad Workers Memorial”. https://chinatownconcerngroup.wordpress.com/2016/05/13/now-and-then-chinese-railroad-workers-memorial/
Frey, W. (2017). Chinese workers integral in building Canada's first megaproject. Construct Connect. https://canada.constructconnect.com/Leaders2017/chinese-workers.html
.
CHIROPRACTIC & MANUAL THERAPIESClar et al. Chiropractic & .docxbissacr
CHIROPRACTIC & MANUAL THERAPIES
Clar et al. Chiropractic & Manual Therapies 2014, 22:12
http://www.chiromt.com/content/22/1/12
SYSTEMATIC REVIEW Open Access
Clinical effectiveness of manual therapy for the
management of musculoskeletal and non-
musculoskeletal conditions: systematic review
and update of UK evidence report
Christine Clar1, Alexander Tsertsvadze1, Rachel Court1, Gillian Lewando Hundt2, Aileen Clarke1 and Paul Sutcliffe1*
Abstract
Background: This systematic review updated and extended the “UK evidence report” by Bronfort et al. (Chiropr
Osteopath 18:3, 2010) with respect to conditions/interventions that received an ‘inconclusive’ or ‘negative’ evidence
rating or were not covered in the report.
Methods: A literature search of more than 10 general medical and specialised databases was conducted in August
2011 and updated in March 2013. Systematic reviews, primary comparative studies and qualitative studies of
patients with musculoskeletal or non-musculoskeletal conditions treated with manual therapy and reporting clinical
outcomes were included. Study quality was assessed using standardised instruments, studies were summarised, and
the results were compared against the evidence ratings of Bronfort. These were either confirmed, updated, or new
categories not assessed by Bronfort were added.
Results: 25,539 records were found; 178 new and additional studies were identified, of which 72 were systematic
reviews, 96 were randomised controlled trials, and 10 were non-randomised primary studies. Most ‘inconclusive’ or
‘moderate’ evidence ratings of the UK evidence report were confirmed. Evidence ratings changed in a positive
direction from inconclusive to moderate evidence ratings in only three cases (manipulation/mobilisation [with
exercise] for rotator cuff disorder; spinal mobilisation for cervicogenic headache; and mobilisation for
miscellaneous headache). In addition, evidence was identified on a large number of non-musculoskeletal conditions
not previously considered; most of this evidence was rated as inconclusive.
Conclusions: Overall, there was limited high quality evidence for the effectiveness of manual therapy. Most reviewed
evidence was of low to moderate quality and inconsistent due to substantial methodological and clinical diversity.
Areas requiring further research are highlighted.
Keywords: Clinical effectiveness, Manual therapy, Systematic review, Musculoskeletal, Bronfort
Background
Manual therapy is a non-surgical type of conservative
management that includes different skilled hands/fingers-
on techniques directed to the patient’s body (spine and
extremities) for the purpose of assessing, diagnosing,
and treating a variety of symptoms and conditions [1-4].
Manual therapy constitutes a wide variety of different
* Correspondence: [email protected]
1Populations, Evidence and Technologies, Division of Health Sciences,
Warwick Medical School, University of Warwick, Coventry CV4 7AL, England
Full list of author info.
Chinese Society 中国社会What are the social voices in China.docxbissacr
Chinese Society
中国社会
What are the social voices in China?
Tradition
Confucianism
Revolution
Communism, Maoism
Reform (Current)
Socialism with Chinese Characteristics?
Capitalism?
Deng Xiaoping Thought?
Harmonious Society (since 2005)
What are the components in Chinese society?
Danwei
Work unit
Guanxi
Connections
Family
One child, two childe
How has Chinese society changed?
Time
Space
Money
Commodification
Landscape
Self
Sex
What are the paths to success?
Mao’s China
Red- politics, White - education
Army, marriage
Deng’s China
Golden - business
To get rich is glorious
Redefining China’s Families
http://www.washingtonpost.com/wp-srv/world/interactives/chinafamilies/
How has the family in China changed?
Young and Restless in China
http://www.pbs.org/wgbh/pages/frontline/youngchina/
What are the lives of people like ?
Hutong Old Beijing
10
PSY 345: Social Psychology
McAuliff
Personal Application Paper
PERSONAL APPLICATION PAPER
In addition to reading and thinking about the concepts covered in the text, an important part of the
learning process includes applying these concepts to your own life and experiences. To facilitate
this process, a personal application paper must be uploaded on Moodle no later than 10am on
Monday, May 11. The paper should be typed (12 characters/inch font), three to five pages in
length, and double-spaced with one inch margins. Late papers will not be accepted and
students not turning in papers will receive a 0. The personal application paper will count
for 25% of your final grade.
For the paper, students should select one or two central topics discussed during the semester and
write about how the topic(s) is relevant to you and your life. For example, for the chapter on
prejudice, you might write about a time you directly or indirectly experienced some form of
prejudice. Alternatively, you could analyze a television commercial with an eye toward the material
covering the use of persuasion to increase compliance. Remember, this assignment is intended to
help you recognize how the material covered in class is personally relevant, as well as to
encourage you to think critically about the concepts presented instead of passively accepting them
as truths. Thus it is acceptable (and commendable) to include in your paper a discussion of the
reasons why you agree/disagree with what the author is saying. To reiterate, each paper must
have the following two components: a review (including proper citation) of the concept from the text
to be discussed; and second, your thoughts/feelings on this topic and a discussion of how it applies
to your life including whether you agree/disagree with what the author has said.
PSY 345: Social Psychology
McAuliff
Personal Application Paper Grading Form
_____ Introduction (2)
_____ Statement of interest (1)
_____ Explained (1)
_____ Description of Social Psychological Concept, Theory, or Research (.
China’s geography
中国地理
China’s physiography
Regional Geography
The same area as the U.S.
1.39 Billion People, 0.3% growth
90 percent live in the Eastern half
NORTHMandarinCoal; wheat;
Heavy industrySOUTHCantonesecotton; rice;
light industryWESTMinoritiesOil;
Agriculture
4
Figure 11-12
Title:
Landscape Regions of China
Caption:
The term China proper denotes the densely populated, culturally Han Chinese areas to the east of the blue line. The Yangtze Valley divides China proper into two general areas. Immediately to the north is the large fertile area of the North China Plain, bisected by the Huang He (or Yellow) River. To the west is the Loess Plateau, an upland area of soil derived from wind-deposited silt after the prehistoric glacial period, about 15,000 years ago.
China/USA
What are the characteristics of China’s territory?
Size of US 9,600,000 sq km
1.39 billion people
mid latitude
Continental
West dry, mountainous
East coastal humid
Vast in territory, rich in resources
Land is scarce, people are many
How do the mountains, rivers and basins combine in China?
Three tiers
SW mountains Tibetan Plateau >3000m
Himalayas, Kun Lun, Karakoram, Tian Shan
Basins and Plateaus 1000-3000m
Tarim Basin, Junggar Basin, Mongolian Plateau (Ordos),
Great Xingan, Chang Bai
Loess Plateau, Sichuan Basin, Yunnan Plateau
South China Hills (Wuyi)
Lowlands <500m
North China Plain, Northeast Plain, Deltas
Karakoram mountains
Tibetan plateau
Everest Chomolongma
Sichuan
Loess plateau
Guangdong
North China
South China
SW - Yunnan
Yellow River - West
Yellow River - East
Yangzi Basin
Yangzi River
Three Gorges Dam
Electrical power
Flood control?
Earthquake
Silt in lake
Aquatic habitat
2 million people moved
Physical environment
Climate
11_04.JPG
18
Figure 11-04
Title:
Flooding on the North China Plain
Caption:
Major flooding, sometimes inundating large sections of the North China Plain, has been a historical problem with the Huang He River. Severe droughts can also plague the same region. Extensive dikes have been built along much of the river to protect the countryside from flooding, as seen in this photo taken near the historical city of Kaifeng. (Yang Xiuyun/ChinaStock Photo Library)
11_05.JPG
19
Figure 11-05
Title:
Denuded Hillslopes in China
Caption:
Because of the need to clear forests for wood products and agricultural lands, China's mountain slopes have long been deforested. Without forest cover, soil erosion is a serious issue. (Bob Sacha/Corbis)
11_07.JPG
20
Figure 11-07
Title:
Coal-Fired Power Plant in China
Caption:
A coal-fired power plant emits large quantities of pollution in northwestern China. As China industrializes, it is building many such plants, damaging local air quality and contributing to global warming. (Natalie Behring/OnAsia.com)
Environmental Challenges
21
China’s population
中国人口
Current stats
http://www.prb.org/
Population Reference Bureau.
China’s reliance on coal epitomizes the central single energy .docxbissacr
China’s reliance on coal epitomizes the central “single energy dilemma” by being dependent upon oil heavily over the last decade. China became a net coal importer in 2009. They have multiple sources that supplies the country in proximity; specifically, Australia, Russia, and Indonesia to name a couple. China is the “second largest economy and destination of foreign direct investment” (Sarah Ladislaw, 2014). China due to the heavy growth must use more energy in order to support the growth. Another source stated that China also imported 5.4 million barrels per day of crude and 706 billion cubic feet of natural gas in 2012 alone. This contributes to the “single energy dilemma” because China seemingly is dependent on imported oils due to the amount of growth that they are experiencing.
In my personal assessment it is likely that China can move away from and off goal due to the development and interest in shale gas which is an alternative to coal. China used 10.7 million barrels of oil per day in 2013 which accounted for one third of global oil demand. Due to shale gas being developed China is rethinking their relationships with the Middle East and North Africa. Their dependence on Middle East supplies continues to grow so there needs to be another option for a country who grows ten percent per decade. There are other avenues other than the Middle East. For example, China has been looking into resources closer to home such as central Asian countries for oil. In conclusion China can move away from and off coal with the development of great relationships closer to home.
Sarah Ladislaw, M. L. (2014).
New Energy, New Geopolitics.
Bradshaw, M. (2013).
Global Energy Dilemmas.
.
chinese civilization essay question text 2-3 pages Cours.docxbissacr
chinese civilization essay question text
2-3 pages
Course Syllabus
Jump to Today
Chinese 10: Chinese Civilization
Instructor:
Dr. Jingyu Xue
Email:
[email protected]
Class Hours:
W 3:45-6:55 pm, Room R219
Office Hours:
before and after class, or by appointment
COURSE DESCRIPTION:
This course traces the development of Chinese civilization, one of the world’s oldest continuous civilizations, from Neolithic times down to the present. It covers the study of Chinese geography, philosophy, religion, political environment, social relations, family and gender roles, literature, art and drama. Classes will be a combination of lecture and discussion, and students are expected to participate in classroom discussion in order to better understand the rich heritage and full complexity of Chinese culture.
This class will be taught entirely in English. No prior knowledge of Chinese language or culture is required.
TEXTBOOK:
All required readings will be posted on Canvas.
Recommended textbook:
Ebrey, Patricia.
The Cambridge Illustrated History of China, 2nd
edition.
Cambridge: Cambridge University Press, 2010.
STUDENT LEARNING OUTCOMES:
After the completion of this course, students will be able to perform the following tasks:
Describe the major geographic features of China.
Describe the historical contributions of important people in Chinese history.
Explain at least two aspects of Chinese culture and aesthetic tradition.
Analyze various religious influences in China.
Compare/ contrast the differences between the Western and Chinese cultures in family, artistic, and philosophical values.
REQUIREMENTS:
Attendance is mandatory and factored into your participation grade. A student who arrives more than 10 minutes late or leaves more than 10 minutes early will be marked as half-absence. More than 1 unexcused absence will adversely affect your participation grade (10 points out of 100 will be subtracted for each absence). Any student who is absent 3 times in a row will be dropped from the class. An appropriate document is required for all excused absences.
All required readings will be posted on Canvas
. Students are expected to complete reading the assigned texts before coming to each class. It is very important to keep up with the weekly reading assignments and come to class with your textbooks and notes. By doing so, you will be better prepared to participate in class discussion
Active and informed participation in class discussion is required. The final grade can be raised or lowered a few points based on participation. Also, answers to all the exam questions will be addressed during class lectures and discussion. Please be sure to pay close attention and take careful notes. Please turn off all cell phones, pagers and other electronic devices during our class sessions.
Academic Honesty
. All written assignments must be original work put in an individual student’s own words. They can never be copied from another student,.
ChinaThe Third RevolutionXi Jinping and the New Chinese Sta.docxbissacr
China:
The Third Revolution
Xi Jinping and the New Chinese State
Elizabeth Economy
Elizabeth Economy, PhD
Council on Foreign Relations:
C. V. Starr senior fellow
Director for Asia studies
Hoover Institution of Stanford University
Visiting Fellow
She is an acclaimed author and expert on Chinese domestic and foreign policy, writing on topics ranging from China's environmental challenges to its role in global governance.
BA – Swarthmore; MA – Stanford; PhD – University of Michigan
Primary Theses
1. Xi Jinping has steered politics and economics towards repression, state control, and confrontation
Xi Jinping has used his power to reassert dominance of the Communist Party and of his own position within it
As part of the campaign against corruption, he has purged potential rivals
He has executed sweeping reorganization of the People’s Liberation Army to ensure loyalty of the military to the party and to him personally
Mr. Xi has imprisoned supporters of Western liberal reform and stamped out criticism of the party and government in the media and online
He has created a surveillance state to monitor discontent and deviance.
China increasingly controls business as an arm of state power
Made in China 2025 plan uses subsidies and protection to create world leadership in ten industries including aviation, tech & energy
Belt and Road Initiative subsidizes infrastructure development in Asia and Africa in return for Chinese trade agreements
c. Regional production chains or production networks are the mechanism by which China influences Asian economies and integrates itself with the global economy.
Enables higher degree of specialization and integration
Facilitates exploitation of scale and scope economies
Ideologically, Chinese path is captured in the “Chinese Dream”
The Third Revolution
The Rejuvenation of the Great Chinese Nation
Common Factors that Explain Takeoff
Openness to trade and investment – higher than rest of world
Strong Export Demand in advanced industrial economy
Increasing intra-regional trade
High Domestic Savings & Investment Rates
Strengthened physical and digital infrastructure
Improved quality of human capital
Active Government Involvement in Economy
Openness to trade
Share of Asian trade as % total world trade increasing at expense of European and Russian trade
North American trade relatively stable.
China: export partners in 2016, by export value
(in billion yuan)
United States
“…other than trade and FDI (foreign direct investment), regional production chains or production networks became a mechanism by which Asian economies tangibly influenced each other as well as integrated in a market-led manner. As barriers to the movement of goods, services and factors of production are dropped further, Asian economies would integrate more with each other as well as with the global economy.” Das, p. 13
Enables higher degree of specialization and integration
Facilitates .
Chinas first emperor, Qin, unified the different territories and st.docxbissacr
China's first emperor, Qin, unified the different territories and states into one empire. Discuss the importance of "standardization" (coins, stamps, language, etc.) in that unification.
Need at least two sources minimum and all sources need to be cited.
Minimum 300 words, maximum 500 words.
.
Chinas Great Wall Please respond to the following, using sources.docxbissacr
China's Great Wall" Please respond to the following, using sources under the Explore heading as the basis of your response:
Describe two (2) specific aspects about the Great Wall of China, such as facts about its size, length, purposes, varied materials, labor force, and its phases of construction. Consider the various purposes of such a wall and its impact for good or bad, and compare the Chinese wall in this respect to some specific wall of more modern times.
Compare and contrast the Great Wall of China with The Tomb and Terra Cotta Warriors of Qin Shihuangdi. Which is his greatest legacy?
Or, take the opposite approach and present the case that neither was Qin Shihuangdi’s greatest legacy.
Explore
China and Its Great Wall
•Chapter 7 (pp. 212-213, 220), early phases, (p. 605) later phase
•Explore wall interactively at http://www.panoramas.dk/7-wonders/great-wall.html
•Video at http://www.discovery.com/tv-shows/other-shows/videos/discovery-atlas-china-revealed-the-great-wall.htm
•UNESCO article at http://whc.unesco.org/en/list/438
•“China’s Wall Less Great in View from Space” article at http://www.nasa.gov/vision/space/workinginspace/great_wall.html
.
China1. Assess and include transcultural beliefs including l.docxbissacr
China
1. Assess and include transcultural beliefs including language, religious practices, socioeconomic status, end-of-life practices, dietary preferences, risky behaviors
2. Identify healthcare behaviors (i.e. nontraditional therapies)
3. Identify challenges and barriers to healthcare and outcomes related to these challenges
4. Develop an evidence-based plan that can be used to improve healthcare outcomes and access to healthcare (including use of IT systems, interdisciplinary members, etc.) for your selected culture. Provide supporting data from peer-reviewed articles
.
APA formatted, 2-page paper
Minimum of 3 references within 5 years
.
China, also known as the Peoples Republic of China or PRC, is a cou.docxbissacr
China, also known as the People's Republic of China or PRC, is a country located in the east of Asia. It is the largest Asian country and has the biggest population in the world at around 1.4 billion. Its ruling and founding political party is called the
Communist Party
wherein the head of state is the President, elected by the National People's Congress. He supervises the state council which consists of four vice premiers and the heads of ministries and commissions.
Although Human rights are exercised in this country, a sample of which is the freedom of speech, it is not freely implemented, since it is limited and firmly restricted by specific regulations and laws. This essay will tackle the restriction of freedom of speech in China.
Limited Freedom of Expression
Freedom of expression is the right to convey one’s opinions and thoughts without fear of being punished by the country's government. And although a lot of countries are exercising freedom of speech, some countries like China don't have this as one of their basic human rights.
As a sample, during the 2008 Summer Olympics, the Chinese government agreed to release permits allowing the people to protest in specific areas designed as protest parks in Beijing, but most of the applications sent to the government were either refused, banned or withheld and the police authorities even apprehended the people who applied for permits. If you are looking for essay examples, for example, a
freedom of speech persuasive essay
, it would impossible to find an essay that cites controversial issues. This is because access to web pages considered by the authorities of China as "threatening" or "risky" to the Communist Party are blocked on the internet.
On the brighter side, The Chinese government is spending huge amounts of money on catching and blocking not only web pages that advertise political change within the country, but also websites which may have violence and pornography. According to the Constitution of the People's Republic of China, Chinese citizens can enjoy the freedom of the press and freedom of speech.
However, these kinds of freedom are not institutionally protected. Public speeches that consist of forbidden subjects that can have a huge impact on the people could result in a penalty by the government, and that can include criminal sentences.
As a country ruled by
communism
, it does not accept any disapproval or protest from its people, and other parties defying the government and criticizing them are at risk of persecution. As a Chinese citizen, you are not allowed to freely use social media and have access to western news since it is also controlled by the government.
Other Restrictions
Aside from the government's restriction on freedom of speech, there are other limitations and regulations as well, such as on the administration of publishing and radio and television administration. According to the constitution regarding the administration of publication, .
china & USA ----Food curlture1 follow news story, and related curr.docxbissacr
china & USA ----Food curlture
1 follow news story, and related current events, for the entire semester, using diverse global news sources.
2 utilize diverse reference materials and peer reviewed academic journal articles across disciplines
3 present and explanation of research three times during the semester news report days.
NEWS report presentation rubric
outline
completion
format
detail
source list
cotent
accuracy&depth of research
connection to texts&class discussions
questions raised for further research
significant contribution to group
diverse sources
slant/bias considered or acknowledged
quality of sources
style
pace&volume
clarity
creativity
enthusiasm
.
Palestine last event orientationfvgnh .pptxRaedMohamed3
An EFL lesson about the current events in Palestine. It is intended to be for intermediate students who wish to increase their listening skills through a short lesson in power point.
Honest Reviews of Tim Han LMA Course Program.pptxtimhan337
Personal development courses are widely available today, with each one promising life-changing outcomes. Tim Han’s Life Mastery Achievers (LMA) Course has drawn a lot of interest. In addition to offering my frank assessment of Success Insider’s LMA Course, this piece examines the course’s effects via a variety of Tim Han LMA course reviews and Success Insider comments.
2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
Knowledge and skills frameworks, generally called competency frameworks, for ELT teachers, trainers and managers have existed for a few years now. However, until I created one for my MA dissertation, there wasn’t one drawing together what we need to know and do to be able to effectively produce language learning materials.
This webinar will introduce you to my framework, highlighting the key competencies I identified from my research. It will also show how anybody involved in language teaching (any language, not just English!), teacher training, managing schools or developing language learning materials can benefit from using the framework.
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
Read| The latest issue of The Challenger is here! We are thrilled to announce that our school paper has qualified for the NATIONAL SCHOOLS PRESS CONFERENCE (NSPC) 2024. Thank you for your unwavering support and trust. Dive into the stories that made us stand out!
The Roman Empire A Historical Colossus.pdfkaushalkr1407
The Roman Empire, a vast and enduring power, stands as one of history's most remarkable civilizations, leaving an indelible imprint on the world. It emerged from the Roman Republic, transitioning into an imperial powerhouse under the leadership of Augustus Caesar in 27 BCE. This transformation marked the beginning of an era defined by unprecedented territorial expansion, architectural marvels, and profound cultural influence.
The empire's roots lie in the city of Rome, founded, according to legend, by Romulus in 753 BCE. Over centuries, Rome evolved from a small settlement to a formidable republic, characterized by a complex political system with elected officials and checks on power. However, internal strife, class conflicts, and military ambitions paved the way for the end of the Republic. Julius Caesar’s dictatorship and subsequent assassination in 44 BCE created a power vacuum, leading to a civil war. Octavian, later Augustus, emerged victorious, heralding the Roman Empire’s birth.
Under Augustus, the empire experienced the Pax Romana, a 200-year period of relative peace and stability. Augustus reformed the military, established efficient administrative systems, and initiated grand construction projects. The empire's borders expanded, encompassing territories from Britain to Egypt and from Spain to the Euphrates. Roman legions, renowned for their discipline and engineering prowess, secured and maintained these vast territories, building roads, fortifications, and cities that facilitated control and integration.
The Roman Empire’s society was hierarchical, with a rigid class system. At the top were the patricians, wealthy elites who held significant political power. Below them were the plebeians, free citizens with limited political influence, and the vast numbers of slaves who formed the backbone of the economy. The family unit was central, governed by the paterfamilias, the male head who held absolute authority.
Culturally, the Romans were eclectic, absorbing and adapting elements from the civilizations they encountered, particularly the Greeks. Roman art, literature, and philosophy reflected this synthesis, creating a rich cultural tapestry. Latin, the Roman language, became the lingua franca of the Western world, influencing numerous modern languages.
Roman architecture and engineering achievements were monumental. They perfected the arch, vault, and dome, constructing enduring structures like the Colosseum, Pantheon, and aqueducts. These engineering marvels not only showcased Roman ingenuity but also served practical purposes, from public entertainment to water supply.
Unit 8 - Information and Communication Technology (Paper I).pdfThiyagu K
This slides describes the basic concepts of ICT, basics of Email, Emerging Technology and Digital Initiatives in Education. This presentations aligns with the UGC Paper I syllabus.
How to Make a Field invisible in Odoo 17Celine George
It is possible to hide or invisible some fields in odoo. Commonly using “invisible” attribute in the field definition to invisible the fields. This slide will show how to make a field invisible in odoo 17.
Model Attribute Check Company Auto PropertyCeline George
In Odoo, the multi-company feature allows you to manage multiple companies within a single Odoo database instance. Each company can have its own configurations while still sharing common resources such as products, customers, and suppliers.
Chemistry of life (Biochemistry) The study of chemical .docx
1. Chemistry of life (Biochemistry)
The study of chemical compounds that are vital for
living organisms to sustain life is called biochemistry. The
subject deals with the nature of these compounds and
characteristic reactions they make inside the living
organisms . We are not involved fundamentally with the
study of biochemistry as a subject , but to give brief
introduction to main classes of the organic compounds in
this important field. It is beyond this discussion to present
detailed explanation of these essential organic substances .
We will give short introduction of the main classes and
their active role in our body . Some of these groups are ,
carbohydrates , fats and proteins, etc..
· Carbohydrates.
Carbohydrates are classes of organic compounds that
consist of carbon , hydrogen and oxygen with an empirical
formula of Cm(H2O)n in most cases . The terms m and n
can be the same as in the case of C6H12O6 (glucose) or
different in the case of C12H22O11 (sucrose) . Another
important feature of the carbohydrates is that oxygen and
hydrogen are generally in ratio of 2:1 , so that it was
historically called hydrates of carbon ; but not all
compounds of carbohydrates necessarily maintain this
hydrogen – oxygen ratio and not all compounds that fit
this hydrogen-oxygen ratio are carbohydrates .
In biochemistry the term carbohydrate denotes different
compounds called saccharides . These compounds include
sugars , starch and cellulose . Saccharides (Greek word
meaning sugars) are generally classified into
monosaccharides , disaccharides and polysaccharides .
Monosaccharides are the simple sugars which are either
aldoses (aldehydes) like glucose or ketoses ( ketones) like
2. fructose . These simple sugars are further classified on the
base of the number of carbon atoms they contain like
pentose (containing five carbon atoms) , or hexose
(containing six carbon atoms) .
Carbohydrates are naturally formed in a process called
photosynthesis in which plants combine CO2 from the air
and water from the soil in the presence of chlorophyll ,
sunlight and certain enzymes producing simple sugars .
6 CO2 + 6H2O (sun light) C6H12O6 + 6O2
sugar(glucose)
This above reaction is not simple process as it looks ,
but extremely complicated reaction with different
intermediate steps before it gives the final product . since
the final product is a monosaccharide , plants have the
ability to synthesize disaccharides by combining two
molecules of monosaccharides .
2 C6H12O6 C12H12O11 + H2O
monosaccharide
disaccharide
This above natural chemical process is the reverse of
hydrolysis . Both plants and animals have the ability to
synthesize polysaccharides by combining large number of
monosaccharide molecules .
n C6H12O6 (C6H10O5)n + n H2O
polysaccharide in plants are usually in the form of
cellulose , stored in stalks and stems and in a form of
starch in the roots and seeds .
Animals and plants depend on each other to sustain life ;
plants can synthesize carbohydrates - as we mentioned
3. before - from simple inorganic materials like CO2 and
H2O while animals cannot. On the other hand , animals
utilize these essential carbohydrates and metabolically
oxidize to give CO2 , water and energy .
C6H12O6 + 6 O2 6 CO2 + 6H2O + energy
Note that this reaction is the reverse of that of the
photosynthesis in plants ; we can combine both equations
to establish the relationship .
The reaction to the right is endothermic and the energy
is taken from the sunlight while the reaction to the left
is exothermic in which the same energy is liberated and
utilized by the body activity to sustain life .
It is clear from this cycle that the energy stored in the
carbohydrates is originally from the sun .This energy is
used by all living organisms in their metabolic process.
1- Monosaccharides
Monosaccharides are the basic units of the carbohydrates
; they are also called simple sugars . The term
monosaccharide originally came from two Greek words
mono- which means single and Sachar which means sugar .
These simple sugars are usually colorless crystalline solid
material . Almost all monosaccharides are soluble in water
and have sweet taste .
4. Most monosaccharides have chemical formula of
Cm(H2O)n where n < 2 . They are classified - as we already
described - on the base of number of carbon atoms present
in the molecule such as triose , pentose , and hexose
representing glyceraldehyde , ribose and glucose respectively
.
The carbon chain of the monosaccharides are numbered
beginning from the carbon closest to the carbonyl group .
We can also designate the structural nature of the
monosaccharide by using the terms aldoses or ketoses so
that if the carbonyl is at position 1 of the carbon chain ,
the sugar is an aldehyde and termed an aldose . On the
other hand if the carbonyl group is in between two
carbon atoms , then the sugar is ketone and termed ketose .
· Structures of monosaccharides – (optical isomers).
Monosaccharides exist in different stereo-isomeric forms .
In section (10.3) of this chapter , we presented this
property in detail and explained the two types of the
stereoisomers ; the important one in our study of simple
sugars is the optical isomerism .
Optical isomers are molecules that have the same
molecular formula but differ in the arrangement of the
atoms in space in such a way that they are mirror images
to one another . Despite these isomers have the same
physical and chemical properties , they differ in the
direction of rotating planely polarized light (light waves
vibrating in one plane ) . If polarized light is passed
through these isomers, the plane of the vibrating light is
5. rotated due to presence of chiral or asymmetric carbon in
the molecule that is a carbon atom attached to four
different groups . Suitable example is the glyceraldehyde
molecule .
The central carbon atom is connected to aldehyde group
, OH group , hydrogen and alcoholic group . Despite
glyceraldehyde is the simplest carbohydrate , it is very
important compound in the since that many complex
sugars can be derived .
· Classification of monosaccharides
We have seen that simple sugars can be divided into
different groups depending on the number of carbon atoms
they contain designating them as trioses , tetroses, pentoses
and hexoses.
A. Trioses: These are monosaccharides that consist of three
carbon atoms . Glyceraldehyde is an example of this group
. Trioses are the product of the metabolic breakdown of
certain simple sugars .
B. Tetroses: Tetrodes are simple sugars with four-carbon
structure . Erythrosine and throes are examples of these
sugars .
6. C. Pentose: These are monosaccharides with five-carbon
atoms . They are classified into two groups ; those with
aldehyde functional groups called aldopentose and those
with ketone functional groups called ketopentose .
The most significant of these sugars are the ribose and
deoxyribose which are found in RNA (Ribonucleic acid)
and in DNA (Deoxyribonucleic acid) . Both RNA and DNA
are the main component of every living cell , especially in
the nucleus of the cell .
D. Hexoses: They are monosaccharides with six carbon
atoms . There are different kinds of hexoses but the most
important ones in terms of human body are glucose ,
fructose and galactose . These sugars have the same
chemical formula but differ in structure and can be called
isomers of a given molecular formula .
We already explained that simple sugars are classified on
the base of their functional groups . Hexose with aldehyde
functional group are called aldohexose and those with
ketone functional group are called ketohexose .
A. Glucose: glucose is an aldohexose with general formula
C6H12O6 ; there are four asymmetric carbon atoms and 16
7. optical isomers . Glucose molecules can exist in solution in
the form of open chain or in the form of ring structure .
This ring structure is formed when the hydrogen of the
carbon 5 -OH attaches with the oxygen atom of the
aldehyde group on carbon 1 .
Open chain
Ring structure
B. Galactose: galactose is an aldose sugar like glucose ; it
can be considered as the isomer of glucose , they only
differ in the configuration of a single carbon atom which
is known as epimoric form of isomerism (differ in one
stereoisomeric center) . Like any hexose , it can exist in
solution as an open chain or ring form .
Open chain
Ring structure
C. Fructose: fructose is ketohexose with a molecular
formula of C6H12O6 , like glucose and galactose . Fructose
or levulose is naturally occurring sugar found in fruits ;
like any other hexoses , it is found in solution as a ring
8. or as open chain structure . Fructose is the sweetest and
most soluble of all sugars .
Reactions of the hexose monosaccharides
Aldoses and ketoses have reducing properties in common
. These properties are the bases of the chemical tests
undertaken to determine the sugar content in human blood
and urine . The reactions involved in these chemical test
are in the organic practical section . In these tests aldoses
are oxidized into their corresponding acids .
RCHO + Cu2+ + 2 OH-
RCOOH + Cu2O + H2O
Clinitest tablets are used to perform the above test to
determine the sugar in the human urine . Note that these
tablets contain copper ions in the form of Cu(II)sulfate.
Another test for reducing sugars is the Tollens test in a
solution containing silver ions in basic solution .
Glucose + Ag+ + OH- gluconic acid + Ag +
water
9. Another general qualitative test for carbohydrates is the
Molisch test in which concentrated sulfuric acid is
carefully added to the testing solution containing alpha-
naphthol ; formation of purple ring at the interface of the
acid and solution confirms the presence of carbohydrate
substance .
Another important reduction reaction for some aldoses like
glucose is the fermentation process in which an enzyme
from the yeast catalyzes this reaction and without which
this reaction cannot take place .
C6H12O6 enzyme CH3CH2OH + CO2
Aldoses can also undergo oxidation since they both
contain aldehyde and hydroxyl group . We have seen that
oxidation of the aldehyde group gives the corresponding
acid , like gluconic acid in the case of glucose and
glucuronic acid if the hydroxyl group oxidizes .
Aldohexoses can be converted to alcohols by reduction and
in this case , glucose is reduced to sorbitol and fructose is
reduced to mixture of mannitol and sorbitol.
Glucose
Sorbitol
Since both sorbitol and mannitol are partially and slowly
10. taken by the body , it is useful as sweetening agent for
the diabetic people . When orally taken some of the sugar
is excreted in the urine and other is taken by the body
slowly .
1. Disaccharides
Disaccharides are the sugars formed when two
monosaccharides are chemically joined together . The most
common examples of the disaccharides are sucrose , lactose
and maltose . They all have the general formula
C12H22O11 , which means they are isomers .
Disaccharides formed as a result of condensation reaction
of two monosaccharides which means elimination of water
molecule . The reverse reaction is known as hydrolysis
performed by certain enzyme .
These reactions are vital in the metabolism of living
things . Different disaccharides hydrolyze to give two
different or same simple sugars as shown above.
Disaccharides are , like monosaccharides , white crystalline
sweet solids . Their solubility varies from completely
soluble to slightly soluble .
Disaccharide molecule from two simple sugars is formed
by displacing hydroxyl group from one molecule and the
hydrogen ion from the other producing water molecule a
process known as condensation reaction .
Sucrose is formed by the reaction of the aldehyde group
11. of glucose with the ketone group of fructose thus
eliminating the reducing property of the carbonyl; and for
this reason give negative test to reducing reagents. On the
other hand , maltose and lactose have free aldehyde group
and give positive test for both Fehling and Tollens
reagents .
In the case of maltose formation , one aldehyde group of
a glucose reacts with the hydroxyl group of another
glucose leaving one aldehyde group free for reducing
property . In the same way , lactose has one available
aldehyde group ; for that reason maltose and lactose are
reducing sugars while sucrose is not reducing sugar .
These sugars are differentiated analytically on the base of
their fermentation and reducing properties . Both sucrose
and maltose can be fermented by the addition of yeast
which contains sucrase and maltase enzymes . Lactose does
not ferment with the yeast since it does not contain
lactase .
A. Sucrose:
This sugar is known as table sugar ; it is naturally
occurring carbohydrate found in many fruits and vegetables
like carrot roots and pineapples . Sucrose is extracted from
cane and beet sugars and refined to be consumed by the
people. Hydrolysis of sucrose gives a mixture of glucose
and fructose .
This mixture of equal amounts of glucose and fructose is
invert sugar . High concentration of this invert sugar is
found in honey ; this kind of sugar is less prone to
crystallization when cooled .
12. B. Maltose:
Maltose is a disaccharide formed from two units of
glucose . It is commonly known as malt sugar . It is
commercially prepared from hydrolysis of starch . It
generally occurs in germinating seeds .
C. Lactose:
Lactose is also a disaccharide formed from joining of
two units of glucose and galactose . It is found in milk
and that is the reason why it is called milk sugar ; it
differs from the above sugars in the sense that it comes
from animals. We pointed out previously that lactose is
fermented by the enzyme lactase forming lactic acid; this
fermented milk is said to be sour milk. Lactose is also
found in urine of pregnant woman and since it is
reducing sugar , it gives positive test with Fehling or
Benedict solution.
2. Polysaccharides:
Polysaccharides can be defined as the polymeric form of
monosaccharides . These polymers hydrolyze to yield many
monosaccharide molecules . These polysaccharides are
generally formed from five-carbon or six-carbon sugars .
The most common polysaccharides are :
A. Starch
Starch is a polymer of glucose sugars which consist
of around 20% amylose and 80% amylopectin . Amylose is
linear chain of glucose molecules while amylopectin is
branched form of the starch and contain much larger units
of glucose in comparison to amylose . Starches are
insoluble in water .
13. Starch (long chain of glucose units )
Amylopectin (branched form of starch)
Amylose (linear chain of glucose)
The presence of starch is tested with iodine which gives
characteristic deep blue color . Hydrolysis of starch to
simple sugars through several stages giving different
dextrin’s on the process which can be followed by
addition of iodine . Iodine gives no color with simple
sugars and blue color with dextrin’s .
A. Cellulose
Cellulose is also polysaccharide consisting of linear
chain of several hundred to thousands of linked glucose
units . It is an important supporting and structural
component of all plants . Unlike starch , cellulose is not
affected by the digestive human enzymes and for that
reason helps prevent constipation by making bulk feces of
dietary fiber when taken by human .
14. Cellulose
Cellulose is digested and metabolized by certain animals
like ruminants and termites with the help of micro-
organisms which live in their abdomen . Cellulose is not
soluble in water and in majority of solvents . Unlike starch
, it does not give positive test to iodine or to Fehling
reagent . Materials like cotton , wood and paper are mainly
composed of cellulose . Cellulose is used to produce paper
, cellophane and rayon.
B. Glycogen ,
Glycogen is multi-branched glucose polymer which is
responsible for the storage of energy in animals . Glycogen
is produced by the body and stored in the liver and the
muscles ; it is originated from the animals while starch is
basically from plant origin ; it acts as a reserve or long-
term energy storage . Even though fats act as the primary
energy stores , glycogen energy is necessary for immediate
mobilization to cover a sudden need for glucose.
Glycogen is synthesized in the body cell from glucose
through a process called glycogenesis and hydrolyzed to
give glucose through a process known as glycogenolysis .
Glucose glycogenesis
15. Glycogen glycogenolysis Glucose
C. Dextrin
Dextrin’s are lower molecular weight carbohydrates formed
as a result of starch hydrolysis . Dextrin’s are considered
as an intermediate between the starch and the
disaccharides . It dissolves in water giving sticky colloidal
suspension used in the preparation of adhesives like the
glue on the back of the postage stamp .
1. Lipids (fats)
Lipids are naturally occurring organic compounds ; these
include fats , waxes , fat soluble vitamins and sterols
(steroid alcohols) . It is one of the main sources of food
essential for animals and plants .
Lipids consist of carbon , hydrogen and oxygen and in
certain cases nitrogen and phosphorus . They are insoluble
in water but soluble in organic solvents like alcohol and
acetone . Even though there are different categories of
lipids , we will confine our discussion to simple lipids
which are esters of fatty acids .
· Fatty acids:
There are two types of fatty acids ; saturated fatty acids
which contain single bond between the carbon atoms and
unsaturated fatty acids which contain double between the
carbon atoms .
17. Linolenic acid
C17H29COOH (3 double bond)
Linseed oil
Unsaturated fatty acids can exist in two structural forms
, cis in which the two hydrogen atoms adjacent to the
double bond are on the same side of the carbon chain
and trans in which the adjacent two hydrogen atoms are
on the opposite sides of the carbon atom (discussed in
section 10.3) .
Iodine number
Human body cannot sufficiently synthesize some of the
fatty acids they need and must be obtained from the food
they take . These fatty acids are known as essential fatty
acids . linoleic and linolenic acids are among the essential
acids ; they are found in certain plant oils like peanut ,
soybeans and corn but not in olive oil or cocoanut.
Essential fatty acids have important function in the body
such as the synthesis of prostaglandins (hormone-like
substance with wide physiological activities) .
Iodine number:
The degree or the amount of unsaturation in a given
fatty acid is determined by its iodine number , which is
the amount of iodine consumed by 100 g of the acid.
Iodine reacts with the double bond of the unsaturated
fatty acid , so the higher the iodine consumed the more
double bonds present in that fatty acid .
18. Despite there are different methods for determining
iodine value , they all fall under the iodiometry procedures
. We indicated that the higher the unsaturation for a fatty
acid the higher the iodine value . Linseed oil has much
more iodine value than coconut oil which means the
linseed oil is highly unsaturated oil with respect to
coconut oil . In general , vegetables oils have higher iodine
number than animal fats .
Fats and oils
We defined the fats as esters of fatty acids (already
discussed in carboxylic acids unit) which are formed from
the reactions between a fatty acid and specific alcohol
called glycerol .
There are three OH groups available in glycerol and
each one can react with a fatty acid molecule forming a
fat molecule . These fatty acids can be of same fatty acids
or different fatty acid molecules .
19. The esters formed when the alcohol is glycerol is called
glyceride . It can be monoglyceride , diglyceride or
triglyceride depending on the number of fatty acids
reacted with the glycerol .
In general if the reacting fatty acid is saturated , the ester
formed is called fat and if it is unsaturated the resulting
ester will be an oil . Most fats have iodine value less than
70 while most oils have iodine value more than 70 . Keep
in mind that mineral oil is a saturated hydrocarbon
different than fats and oils which are either from animal ,
vegetable origin and petroleum distillate .
Those oils are different from essential oils which are
volatile liquids used as flavors and perfumes , while
mineral oils are mixtures of higher alkanes . The name
may be inappropriate and sometimes other names are
applied such as liquid paraffin , paraffin oil etc. .
· Properties and uses of fats
Fats can be considered as body fuel , they produce
more energy for the body than any other nutrient such as
carbohydrates or proteins . Another important function of
the fats is their essential role in reserving food supply for
the body . They protect the vital organs by keeping them
rigid in their place and helping to absorb shocks .
In terms of physical properties , fats and oils are either
in liquid or solid state with white or yellow color in
most cases . They are colorless and tasteless in their pure
state but get rancid as the time goes on creating
unpleasant odor and taste. Since both fats and oils are
insoluble in water ; they form transient emulsions which
can be stabilized by adding emulsifiers from the bile to
make them digestible .
In terms of chemical properties , fats hydrolyze in the
20. presence of certain enzymes to form fatty acids and
glycerol . We have seen that when a fat is formed water
is the product (see the preceded equation) ; the reverse
process is called hydrolysis.
After the hydrolysis of the fat , the glycerol is separated
and purified for medical and industrial purposes . It is
used as humectant (against loss of moisture) for skin and
hair care products . It is also used in the preparation of
medical and pharmaceutical products . Glycerol has also an
important industrial applications ; it is found in food ,
beverages and sweetener as sugar substitute besides many
other uses .
We briefly explained in this chapter , that basic
hydrolysis of fats yield glycerol and salt of the fatty acid
; this process is called saponification and the sodium or
potassium salt formed is called soap .
Sodium soaps are solid bars and potassium soaps are
liquid . In preparing soaps, various materials are added to
give pleasant odor and color ; in certain soaps , germicidal
substances are added to protect the skin from the germs
as in the case scouring soap .
In hard water , calcium and magnesium ion react with the
soap rendering it insoluble and inactive to give more
21. lather and more cleansing result . This problem is
overcome by using detergents . Detergents are synthetic
cleaning substances consisting of mixtures of surfactants
(lower the surface tension) used as a soap . They can be
used both in soft and hard water ; which means calcium
and magnesium salts of detergents are soluble in water
thus overcoming the disadvantage of soap .
Detergents are made from different petrochemicals besides
fat and oils . They are generally neutral unlike the soaps
which are alkaline . The sodium salt of the detergents is
prepared by the reaction of long chain alcohols with
concentrated sulfuric acid and the product is neutralized
by sodium hydroxide .
R-OH + H2SO4 R- OSO3H + H2O
long chain alcohol
R- OSO3H + NaOH R-OSO3Na + H2O
Detergent
The unbranched straight chain detergents are less harmful
in terms of environmental pollution .
2. Proteins
Another essential nutrient for living organisms is the
protein . Proteins are complex organic substance which
consist of carbon , hydrogen , oxygen and nitrogen besides
some other elements like sulfur and phosphorus . Proteins
consist of long chain of simple molecules called amino
acids arranged in a specific order. There are 20 known
amino acids .
All of these amino acids cannot be synthesized by the
human body and must be externally supplied . The first
22. three amino acids are shown below with their symbol and
names
Amino acid molecule contains amino group and carboxylic
group .
Despite the amino group can be structurally anywhere in
the molecule , the amino group of the naturally occurring
amino acids are bonded with the alpha – carbon (the one
next to acid group ). Almost all amino acids have alpha
chiral carbon (except glycine) and show L-configuration .
Amphoteric nature of the amino acids
Amphoteric substance is one that shows both acidic and
basic character ; which means it behaves as an acid and
base. As the name denotes , amino acids contain carboxylic
group which is an acid since it furnishes proton in
solution and also contain amino group which accepts the
proton and on the base of Brnsted – Lowry acid-base
definition , amino acids act as an acid and as a base at
the same time; therefore amino acids react with both
acidic and basic substances ; consequently amino acids can
be called amphoteric substance as long as they donate and
accept protons .
23. Amino acid molecules react together in which the amino
group of one amino acid reacts with the carboxylic group
of another forming a long chain of amino acid molecules
connected through a bond known as peptide bond . This
bond is formed as a result of condensation reaction in
which one molecule of water is produced for every two
reacting amino acids .
A combination between two amino acids form a product
called dipeptide , and that of three amino acids form
tripeptide and more than three amino acids form
polypeptide. There are two different ways for two amino
acids to combine .
It is very important to know that for combined amino
acids , their name is abbreviated by taking the first three
letters of the amino acid and in the order of their
combination in the peptide ; the first amino acid is the
24. one that furnishes the OH from the acid group .
· Isoelectric point
We have seen that amino acids contain both basic and
acidic functional groups. In the crystalline forms , amino
acids exist as zwitterions , which is a neutral molecule
having both positive and negative electrical charges
resulting no net electric charge. These solid forms usually
have high melting point and less solubility in organic
solvents but soluble in water . In aqueous solution , these
amino acids establish an equilibrium dependent on the pH
of the solution .
isoelectric
point
In basic solution , the equilibrium is shifted towards the
right and in acidic solution the equilibrium is shifted
towards the left . If two electrodes are placed in this
amino acid solution , there will be net migration of the
solute molecules towards either the positive electrode
(cathode) or the negative electrode (anode) depending on
the alkalinity or acidity of the solution .
In basic solution a negatively charged carboxylic group is
formed and the migration takes place towards the
positively charged electrode and in acidic solution , a
positively charged amino group will be formed and the
migration takes place towards the negatively charged
electrode .
25. At certain pH , characteristic of each amino acid , the
positive and the negative ions will be equal and there
will be no net migration of the amino acid molecules
towards the electrodes . This specific pH value is called
isoelectric point .
Proteins like amino acids have an isoelectric point which
is characteristic property for each protein . Proteins have
the minimum solubility in their isoelectric point .
For the pH of the amino acid above the isoelectric point ,
the basicity dominates , that is there will be more basic
sites and the pH below the isoelectric point , the acidity
will dominate and there will be more acidic sites .
· Structure and the properties
Proteins hydrolyze in acidic or basic media , or by the
action of certain enzymes . This hydrolysis breaks the
protein molecule into the constituent amino acids . In the
reverse process , amino acids combine together with the
help of specific enzymes to form polypeptides which are
the basic molecular structures of the proteins ; the more
units of amino acids combined the bigger the molecular
weight of the protein .
As a result of the large molecular sizes of the proteins ,
different structural forms are created which are referred to
as primary , secondary and tertiary structures based on the
shape and spatial orientation of the protein molecule .
The bases of these shapes and their biological significances
is beyond our discussion. The main properties of the
proteins can be summarized as follows :
26. A. Colloidal
The aqueous solution of protein form colloidal dispersion
of the protein molecules in water . These colloidal particles
have the ability to pass through the filter paper but inable
to pass thhrough the cellular membranes ; this phenomenon
is physiologically important since it keeps the protein in
the bloodstream and impedes the diffusion of protein
molecules into the urine indicating the damage of kidney
membranes .
B. Denaturation
Denaturation refers to change of protein structure loosing
its biological function . When proteins become denaturated ,
they coagulate or precipitate . This effect takes place under
the influence of several reasons :
1. Effect of alcohol: 70% aqueous solution of alcohol
(ethanol) precipitates almost all proteins and for this
reason we use this alcohol concentration as a disinfectant
because it coagulates the protein of the bacteria rendering
it inactive .
2. Salting out process: at high concentration of salt solution
, proteins become almost insoluble and precipitate . This is
one of the techniques used to separate proteins from
solutions . Salts like Na2SO4 , NaCl are used for this
purpose . The separation from the solution is achieved
through filteration and the traces of the remaining salt is
eliminated by a process known as dialysis .
3. Heavy metal salt : Saturated salt solutions of certain
heavy metals such as silver and mercury(II) precipitate the
protein . These heavy metal salts coagulate the protein
27. making it biologically inactive . This is the reason why
these metals are poisonous if taken internally .
4. Heating :
Almost all protein coagulate on heating . Heating is
common method to sterilize materials because the protein
of the bacteria is destroyed by coagulating it . Presence of
protein in urine (which is kidney malfunction) can be
determined by heating given sample of urine to
precipitate the protein .
5. Concentrated inorganic acids:
Concentrated strong mineral acids can be used to
precipitate the protein. HCl , H2SO4 , and nitric acid are
among the mineral acids that can be employed to
precipitate proteins . Concentrated HCl from the gastric
glands precipitate the milk protein , casein , in the form of
curds .
C. Qualitative tests for proteins
Most qualitative tests for proteins depend on specific color
formation . These tests are not always decisive since it
depends on the presence of certain amino acids . Some of
these tests are :
Xanthoprotic : Which is the formation of yellow precpitate
due to action of nitric acid on proteins . Contact of nitric
acid on your finger usually produces yellow color on the
skin of the finger . This test is only positive for the
amino acids that contain benzene ring .
There are other well known tests like , Biuret , Millon’s ,
Hopkin-Cole and ninhydrin tests in which their procedures
are explained in the organic practical section. Different
28. chromatographic methods are used to separate and identify
different mixture of proteins or amino acids .
Quantatively the amount of protein in a sample is
estimated by determining the nitrogen content and
multiplying the result by factor 6. This factor came from
the fact that the average percent of nitrogen in protein is
16% by weight ; that is approximately 1/6 of the total
weight of the protein . If for example the total nitrogen of
a sample is 2.5 g , the amount of protein present in the
sample = . The result is always expressed in percent .
Nucleoproteins
Nucleoproteins can be defined as conjugated propteins that
consist of acidic part which is nonprptein section called
nucleicacid and a protein part . Nucleoproteins hydrolyze
during the digestion process into nucleic acids and
proteins . Proteins further hydrolyze into amino acids while
nucleic acids hydrolyze into nucleotides .
Nucleic acids are biological polymers that consist of
repeating units of nucleotides so that nucleic acids can be
called polynucleotides . Each nucleotide consist of
heterocyclic nitrogen base , pentose sugar and phosphoric
acid . The number of nucleotide units in a nucleolic acid
depends on the nature of the nucleic acid and may range
29. from approximately one hundred units to several million
units .
Nucleotide
There are mainly two branches of nucleic acids :
a) Deoxyribonucleic acid (DNA) which is found in the
nucleus of the cell and contains pentose sugar ,
deoxyribose , which is the only sugar on hydrolysis.
b) Ribonucleic acid (RNA) which is mainly found in
cytoplasm and contain ribose as the only sugar on
hydrlysis .
Parts of nucleotides
We have showed that a nucleotide consist of nitrogen base
, pentose sugar (ribose or deoxyribose ) and phosphoric acid
. Let us investigate them one by one .
A. Nitrogen bases:
The two groups of heterocyclic nitrogen – containing bases
in the nucleic acids are derivatives of purine or
pyrimidine with following structures .
30. The most common purine bases in nucleic acids are
adenine and quinine . They are present in both DNA and
RNA .
The pyrimidines that are most common in both DNA and
RNA are cytosine , uracil and thymine .
(2-oxy-6-aminopyrimidine) (2,4-dioxy-5-
methylpyrimdine) (2,dioxypyrimidine)
Nucleosides ,
Nucleosides are units formed by combination
of nitrogenous base and one of the two pentose sugars
(ribose or deoxyribose) in the structure of nucleic acids .
In this combination the glycosidic bond between the sugar
and the nitrogenous base is formed at C – 1 of the sugar
and the position 9 of the purine base or position 1 of the
pyrimidine base .
31. Glyosidic between C1 of ribose
Glyosidic between C1 of deoxyribose and
and positon-9 of purine
postion-1 of pyrimidine
Nomenclature
Nucleosides from the pyrimidines have names ending in -
idine and those from the purines have names ending in -
osine Purines with ribose sugars are named as follows :
Adenine + ribose Adenosine
Guanine + ribose Guanosine
Purines with deoxyribose sugars are named as follows :
Adenine + deoxyribose
Deoxyadenosine
Guanine + deoxyribose Deoxy
guanosine
Pyrimidines containing ribose sugars are named as follows
:
Uracil + ribose Uridine
Cytosine + ribose Cytidine
Thymine + ribose Thymidine
Pyrimidines containing deoxyribose sugars are named as :
Uracil + deoxyribose Deoxy uridine
Cytosine + deoxyribose Deoxycytidine
Thymine + deoxyribose Deoxythymidine
32. It is known that glycosides are quite stable in alkaline
medium and the situation is the same in the nucleosides
but hydrolyze in aqueous acid solution to produce base
and pentose sugar .
Polynucleotides Hydrolyze Nucleotides Hydrolyze
Nucleosides Hydrolyze Base + sugar
Nucleotides are the phosphate esters of the nucleosides .
The phosphoric acid reacts with one of the hydroxyl
groups in the sugar forming phosphate ester bond.
Condensation reaction
In the case of ribonucleoside , the phosphate ester bond
can be formed at three possible -OH groups at C1 , C3
and C5 and for that reason we have to specify the point
of the attachment in naming the nucleotide .
We already pointed out that nucleotides are phosphate
esters of nucleosides ; and because the compound contains
phosphoric acid , acidic name is given according to the
following table.
Nucleoside + H3PO4
Acidic name of the nucleotide
Adenosine
Adeynilic acid
Guanosine
Guanilic acid
Cytidine
Cytidilic acid
33. Uridine
Uridylic acid
Thymidine
Thymidilic acidic
The nucleoside formed from the reaction of one molecule
of a nucleoside with one molecule of a phosphoric acid is
called monophosphate of that nucleoside . In the case of
adenosine , it is called adenosine monophosphate (AMP) or
Adeynilic acid . If it reacts with one more phosphoric acid
molecule , it is called adenosine diphosphate (ADP) ; and if
three groups are involved it is called adenosine
triphosphate (ATP) .
) AMP)
(ADP)
(ATP)
These phosphate esters , AMP , ADP and ATP perform
vital role in cellular metabolism as high storage of energy
and release that energy from the hydrolysis of phosphate
bonds and pass to the specific reactions that require this
energy to take place . ATP contains the highest amount of
energy in comparison to ADP and AMP. Besides being
body building blocks , certain nucleotides perform
biological activities of their own . Appropriate example can
be taken in the case of cyclic adenosine monophosphate
(cyclic – AMP) which is formed as a result of phosphate
group attached to carbon-3 and carbon-5 of the ribose
sugar . It (cyclic-AMP) acts as messenger in regulating
enzymatic activities in cells that store fats and
carbohydrates.
34. Cyclic adenosine monophosphate (camp)
Certain nucleotides act as Coenzyme . Nicotinamide
adenine dinucleotide (NAD+) is essential for many
biological oxidation-reductions reactions to take place . It
exists in oxidized form (NAD+) and reduced form
transferring electrons from reaction to another .
Exercises:
1. What is the modern definition of organic chemistry ?
Briefly explain the role of organic chemistry in our daily
life.
2. What was the vital force theory and how was it
disproved ?
3. Account for the fact that element carbon has the unique
property of forming so many millions of chemical
compounds .
4. Briefly compare , in general , the physical and chemical
properties of organic and inorganic compounds .
5. Explain the role of carbon dioxide in the natural
formation of certain organic substances like coal ,
petroleum , and natural gas .
6. What are the hydrocarbons ? mention the different classes
of the hydrocarbons on the base of their general structure
. Give an example of each class .
7. Name the following hydrocarbon compounds .
35. 8. Write the structural formula for each of the following
compounds .
A. 3-Methylheptane
B. 2,3-Dimethylpentane
C. 2-Chloro-3-ethylpentane
D. 1,1,2,2-Tetrabromobutane
E. e) 2-Butyne
F. 3,4-Diethyl-1-hexyne
G. 3-Ethyl-2-heptene
9. Write the possible isomers for the following
hydrocarbons .
A. C7H16
B. C6H12
C. C5H10
D. C4H8
E. C6H10
10. How can you determine the nature of the following
hydrocarbons as alkanes, alkenes, alkynes and cycloalkanes .
A. C7H14
B. C6H12
C. C5H12
D. C4H6
E. C3H4
11. How can you distinguish by simple qualitative test
between the following pairs of compounds ?
A. Ethanol and pentane .
36. B. Acetaldehyde and acetone .
C. Acetic acid and ethylamine .
D. Phenol and benzene .
E. Pentane and pentene .
12. Account for the extra stability of benzene in
comparison to ethene (ethylene).
13. Explain what we mean by a functional group . Why it
is important to classify organic compounds on the base of
their functional group ?
14. Distinguish the following compounds as alcohol ,
aldehyde , ketone , carboxylic acid and amine .
A. CH3-COCH3
B. CH3CH(OH)CH3
C. HCHO
D. CH3CH2CO2H
E. CH3CH(NH2)CH3 .
15. Draw the possible structural formula of the following
compounds .
A. C2H6O
B. CH4O
C. C3H6O2
D. C3H8O
E. C2H7N.
16. Complete and balance the following equations .
37. 17. Define the following terms .
A. Fatty acids
B. Esters
C. Oils
D. Acid chlorides
18. Give an example of each of the following reactions .
A. Addition reaction
B. Substitution reaction
C. Elimination reaction
19. What are nucleoproteins ?
20. Explain briefly the hydrolysis product of nucleic acid
.
21. What is the basic difference between the RNA and DNA
in terms of structure ?
22. Write T at the end of the true statement and F at the
end of the false one.
A. Adenosine consist of ribose sugar and pyrimidine base .
B. Hydrolysis of nucleotide gives phosphoric acid and
nucleoside .
C. The nucleoside urosine is made up of uracil and ribose
.
D. The nitrogen containing bases in the nucleic acids are
either derivatives of pyrimidine or pyridine .
E. Uracil is found in both RNA and DNA .
38. 23. Explain the relationship between the plants and
animals in terms of synthesis and utilization of
carbohydrates .
24. Despite that lactose and sucrose have the same
formula (C12H22O11), they give different results to
reducing agents . Explain why ?
25. Write (√ ) at the end of the correct statement and (X)
at the of the incorrect one .
A. Carbohydrates were historically known as hydrates of
carbon . ( )
B. Carbohydrates are synthesized by plants and animals
from inorganic materials . ( )
C. Proteins are essential for living organisms as source of
energy only .
D. Alkaline hydrolysis of fats gives fatty acids .
E. Proteins are polymeric units of amino acids .
F. Large value of iodine number for fats shows more
unsaturated sites of that fat .
G. All the compounds in which the ratio of C to H is 2:1
are necessarily carbohydrates .
H. Nucleosides do not contain phosphate units.
26. Explain the following terms :
a) Fatty acids
b) Isoelectric point
c) Saturated fatty acids
d) Detergents
e) peptide bond.
39. 27. Give reasons for the following statements.
A. All the naturally occurring amino acids are optically active
except glycine .
B. 70% aqueous ethanol is better disinfectant than 100%
ethanol (absolute) .
C. Chiral compounds are optically classified as D and L
forms in their aqueous solutions .
D. Pentose and hexose sugar molecules can exist as ring
form structure .
E. Enantiomers are different than epimers .
C
C
CH
2
OH
OH
OHH
C
C
CH
2
OH
OH
HOH
D -glyceraldehydeL-glyceraldehyde
CHO
C
C
CH
2
45. N - C - COOH
R
H
Amino group
Carboxylic group
HOOC - C - NH
2
H
H
+HCl
HOOC - C - NH
3
+
+Cl
-
H
H
NH
2
- C- COOH + NaOH
NH
2
- C- COO- + Na
+
+ H
2
O
H
H
H
H
reactas base
reactas an acid
H
2
N - CH - C
46. R
1
O
NH - CH - COOH
R
2
Peptide bond
H
2
N - CH
2
- C
O
OH
+ H
2
N - CH - C
O
OH
NH
2
- CH
2
- C -NH - CH - COOH
O
CH
3
Glycine
Gly-ala
+ H
2
O
CH
3
Alanine
O
47. OH
H
2
N - CH
2
- C
O
OH
Glycine
NH
2
- CH - C - NH - CH
2
- COOH
CH
3
O
H
2
N - CH - CH3
+
Alanine
Ala-gly
H
2
O
+
CH
3
6 CO
2
+ 6H
2
O + ENERGY
plant photosynthesis.
animal metabolism
50. OH
OHH
H
C
C
C
C
C
CH
2
OH
OH
OHH
HOH
H
OHH
OH
O
D-(+)-Glucose
D-(-)-Fructose
D-(+)-Galactose
Practical Section
A. Wet chemistry practical’s (inorganic portion)
In the following practical work , we will be confined to
experiments based on wet chemistry or bench chemical
analysis ; these are traditional laboratory tests which
encompasses certain processes like sampling , weighing ,
preparing solutions and performing classical chemical tests
. In ordinary wet chemistry analysis , qualitative and
quantitative results can be obtained , yet it is rarely
employed in areas like industry , research centers , forensic
analysis etc. These institutions employ modern chemical
analysis which is extension of the classical analytical
techniques that has been automated and computerized to
51. save time and increase the sensitivity selectivity of the
system .
The following laboratory sessions involves certain
quantitative topics like gravimetry , titrimetry and
qualitative topics on identification methods based on
formation of color , precipitate or evolution of specific gas
.
Practical chemistry is mere laboratory work in which the
theoretical knowledge of the subject is developed and the
necessary skills are acquired . To undertake this work , the
necessary apparatus , equipment and reagents must be
available and become familiar with the students . For any
given experiment , these materials must be planned and
prepared so that the result can be reported in a scientific
manner . The students must have knowledge of the
application of these tools and get acquainted with the
laboratory environment .
We can classify the laboratory tools into two parts:
A. Glassware: which are glass containers used for mixing ,
measuring , holding and heating laboratory reagents ; they
are generally made from durable and chemically inert
materials like borosilicate’s . These glass containers are of
different shapes and sizes used for different purposes.
Some of these laboratory glassware are stated below .
1. Beakers : Beakers are glass containers of almost
cylindrical shape used for heating mixing and holding
samples . They are available in different sizes .
Volumetric Flaska
Elenmeyer Flaska
52. 2. Flasks : Flasks are narrow-necked and wider bottom
glass containers used for measuring preparing and heating
solutions . Volumetric flasks are used for preparing and
diluting solutions of definite concentrations . Erlenmeyer
flasks or conical flasks are used for heating or handling
solutions .
Boiling Flasks
3. Boiling flasks: flat bottom flasks used for heavy duty
boiling. They are available in different forms and shapes
according to their application.
Test tubes
Different boiling flasks
Test tubes holders
4. Test tubes: Small glass tubes resistant to high
temperature used for testing samples especially
qualitative tests .
53. Beakers
5. Funnels : Funnels are laboratory apparatus with a wide
mouth and long pipe like opening at the end used to
transfer liquid substance or finely grinded particles to
avoid spillage . They are usually made of glass , plastic or
ceramic .
Different funnels
6. Burettes: Burettes are long graduated glass tubes with
stopcock at end for drawing accurate amount of a solution
. It is extensively used in analytical chemistry, there are
different sizes and structures
Different burettes
7. Other laboratory glassware: Pipettes are used for taking
fixed volume of a liquid. They are usually made of glass or
plastic materials.
54. Uni-Volume Pipette
Graduated Pipettes
Pipette fillers
Crucibles wash bottles
Desiccator Glass rods
Burette clamp Burette stand Test tube rack
B. Instruments: The other feature of the laboratory equipment
are the instruments. Instruments are devices that help or
facilitate to undertake experimental work .
meter hotplate electronic balance
Mortar and pestle Bunsen burners
Oven Shaker
55. Gravimetric analysis
One of the most accurate and precise methods in
chemical analysis is the gravimetric analysis . In this
method , the analyte is converted to insoluble form by
precipitating from the solution . The precipitate is then
separated , washed , dried or ignited , weighed and
calculated . Perfect example can be taken in the
determination of Cl- content in a given solution by
precipitating as AgCl with silver nitrate solution . After
filtering and drying , the precipitate is weighed and the
chloride content is calculated .
There are different forms of gravimetric analysis , and the
one we are concerned in this discussion is the one in
which the sought for substance is almost completely
precipitated from a solution so that no considerable
amount is lost during filtration , washing and weighting .To
achieve successful analytical result , the following points
has to be fulfilled :
A. The precipitated substance must be sufficiently insoluble
so that we can analytically ignore the dissolved amount .
B. The precipitate particles must be large enough to be
quantitatively filtered and the impurities can easily be
washed .
C. The final precipitate must be a substance of definite chemical
composition after physical or chemical treatments.
· To accomplish these points and obtain almost fine precipitate
particles, the following problems must be overcome too.
1. Co-precipitation, the precipitate formed may contain foreign
impurities from the solution which depends on the nature of
the precipitate and the conditions in which the precipitate
was formed ; this contamination can be due to either the
adsorption of impurities on the surface of the precipitated
particles in the solution or the occlusion of foreign
56. particles during the process of crystallization .
2. Coagulation, is the tendency of adsorption layers of the
precipitate to attract ions of opposite charge forming large
size particles containing solvent molecules .
3. Occlusion, this is the way in which foreign particles are
trapped inside the precipitate during the crystallization . It
is not easy to get rid of the occluded impurities .
4. Post-precipitation, it is the precipitation that takes place
on the surface of the precipitating reagent , usually it
comes from a substance that has common ion with
primary precipitate , e. g CaC2O4 / Mg++ & C2O4- - .
Treatment of the Precipitate
To prepare relatively fine pure precipitate , the following
favorable conditions has to be fulfilled.
A. The precipitation must be implemented in dilute solution
keeping in mind the solubility of the precipitate and
digestion period , to minimize the co-precipitation.
B. Add the reagents together slowly with constant stirring
to create large crystals.
C. Precipitation is done in hot solution provided no
counter effect in terms of solubility and the stability of
the precipitate is resulted.
D. The precipitate should be washed with a suitable
solvent.
Precipitation from Homogenous solution
We have already seen that to create a desirable
precipitate , we must minimize the degree of supersaturation
so that dilute solution of the precipitating agent is gently
and slowly added to the sample solution with a constantly
effective stirring . Even though these techniques maintain a low
degree of supersaturation yet excess of the precipitating
reagent is unavoidable so a technique known as homogenous
precipitation is employed to avoid undesirable effects. In this
method, the precipitating reagent is generated in situ
through chemical process which takes place uniformly
57. inside the solution. Dense precipitate is formed in this process
which can easily be filtered.
There are many different anions that can be generated in
this technique like hydroxyl (OH -) , phosphates (PO43-) ,
oxalates (C2O42-) and sulfates (SO42-). An example can be
taken as the case of precipitating hydrous iron oxide or
aluminum oxide. The precipitating reagent is produced by
the hydrolysis of urea in lower pH .
(NH2)2C=O + H2O CO2 + NH4+ + OH –
This reaction takes place gently below the boiling point of
water. Another example of homogenous precipitation is the
generation of SO42- to precipitate barium (Ba) or lead (Pb)
. The sulfate is generated in situ by heating Sulfidic acid
solution that hydrolyzes as following :
NH2SO3H + H2O H+ + SO42- + NH4+
· Experiment (1): Gravimetric determination of Cl.
Apparatus and reagents
A. 0.1N AgNO3 (dissolve 10.79 g in dilute nitric acid and
dilute to 1liter ) .
B. Conc. HNO3
C. Conc. NH3 solution
D. 3N HCl (take 252 ml of 37% HCl and dilute to liter).
E. Filtering crucibles
Procedure:
Prepare two filtering crucibles by cleaning them with
conc. HNO3 followed by washing with distilled water and
then with conc. NH3 followed by plenty of distilled water
. Record the weight of the crucibles to three decimal
places .
Take 25ml of a dilute sodium chloride solution into each
of two 250ml beaker, add excess of silver nitrate solution
slowly and constantly stirring . Heat almost to boiling for
about ten minutes. Cool the solution and add few drops of the
58. silver nitrate to make sure the precipitation has completed.
Let the two beakers stand still for at least one hour in a
dark place . Transfer the precipitate to the filtering crucibles
by decanting. Wash the precipitate with few ml of 6M HNO3
followed by deionized water. Continue washing until there are
no traces of AgNO3. Dry the precipitate to 110o C. for one
hour. Store the crucibles in a desiccator until they are
cooled to room temperature. Take the weight of the
crucibles and calculate the amount of chloride in the
solution. Report the % yield .
· Experiment (2): Gravimetric determination of sulfate in a
solution.
Sulfate is precipitated as barium sulfate from aqueous
solution by systematic addition of BaCl2 . Despite this
precipitation is fast and quantitative , it has great tendency
to occlude many unwanted anions such as PO43- and
NO3- .
Apparatus and reagents,
A. 0.2M BaCl2.2H2O (dissolve 48.8 g in water and dilute to
1liter) .
B. 6M HCl (half-diluted 37% HCl) .
C. 2 porcelain crucibles.
Procedure : Prepare two porcelain crucibles by cleaning and
igniting at high temperature. Cool the crucibles in a
desiccator . Weigh the crucibles repeatedly to 0.2mg. Take
two 50ml aliquots of the solution sample (SO42-) and
transfer to two 400ml beakers ; add 5ml of 6M HCl
followed by 100ml hot BaCl2 solution quickly with
vigorous stirring. Digest the precipitate for one hour. Filter the
precipitate quantitatively in an ash less filter paper. Transfer
the filter papers and the precipitates into the crucibles .Ignite
the contents until almost constant weight is obtained.
59. Calculate the amount of sulfate in grams.
· Experiment (3): Determination of Barium sulfate by
precipitating from homogeneous solution.
Apparatus and reagents .
A. 0.01M BaCl2.2H2O solution (A.R) [dissolve 1.22 g in
distilled water and dilute to 1liter].
B. Sulfidic acid, (NH2)2SO3H (A.R)
C. Electric Hotplate
D. Filtering crucibles (Porcelain) accurately weighed to
constant value.
Procedure : Take 100ml of the barium chloride solution
into clean dry 250ml – beaker add 1.0g of the Sulfamic
acid . Cover the beaker and heat on an electric hotplate at
980C , continue heating until turbidity begins to appear .
Filter the solution in a porcelain crucible ; wash the
precipitate with warm water twice . Heat the crucible with
precipitate at 6500C to a constant weight and determine
the weight of BaSO4 .
Titrimetric Analysis
This topic falls into a wide field that deals with
quantitative determination of an analyte , it is based on
practically reacting volumes in which the volume of a
standard reagent required to completely consume the
analyte is determined ; this procedure is known as
volumetric analysis.
Volumetric procedures employ reagents whose concentrations
are exactly known. These reagents are known as standard
solutions; the quantity of an analyte is determined from the
volume of the standard solution , this is performed by
carefully adding the standard solution into the system until
the reaction with the analyte is complete , then the volume
of the standard reagent is measured from which , the
quantitative relationship of the sought for substance is
60. calculated . In this procedure , the end of the analyte
reaction is determined by employing an indicating system
to denote the equivalence point during the addition of the
standard solution. This indicating technique is shown by
change in color , redox potential , or self-indicating system .
Accuracy of the volumetric analysis depends on the
accuracy of the preparation of the standard solution .
Therefore , special attention must be made to prepare
standard solution of accurate concentration . This is
achieved by dissolving a carefully weighed quantity of the
pure reagent and diluting to the desired volume . Highly
purified substance called a primary standard solution is
employed to accurately fix the real concentration of the
prepared solution . This process is known as standardization
.
Any substance that can be employed as primary standard
solution should at least has the following properties
A. It must be Commercially available in a very high purity
standard .
B. It must be least affected by heat, light, and humidity.
C. It must have high molecular weight.
Here are some of the compounds usually used as primary
standard solutions :
Substance
Molecular mass
Purity available
Standardization used
Potassium dichromate, K2Cr2O7
294.22
99.9 %
Reducing agent
Potassium hydrogen phthalate(C4H5KO4)
204.23
99.9 %
61. Bases
Sodium carbonate, Na2CO3
105.99
99.9 %
Acids
Potassium iodate, KIO3
214.01
99.9 %
Sodium Thiosulfate
Ethylenediaminetetraacetic Acid disodium salt, 2H2O
372.25
99 %
Metals
Sodium chloride, NaCl
58.45
99.9 %
Silver Nitrate
The importance of a titration is to find out or to estimate the
volume of a standard reagent chemically equivalent to a
given volume of an analyte solution. The point at which
the reaction stops or the analyte is theoretically consumed
is called the equivalence point. The practically observed
point in which the analyte is supposed to react completely is
called the end point. The equivalence point is a theoretical
concept while the end point is a practical concept .
In certain volumetric analysis , the end point is detected
by certain chemical substances that change in color as the
process approaches the equivalence point; these substances
are called indicators .
· Acid–base titrations.
We have studied in details the properties and reaction
of the acids and bases in chapter ( 5 ) ; but in this section
we will confine ourselves to the practical aspect of the
acid – base titrations . In acid – base titrations, given amount
62. of a base solution is applied to exactly determine the
chemically equivalent amount of standard acid solution , in
this reaction aqueous solution of the corresponding salt is
formed ; this process is called neutralization process.
Different indicators are used to determine the equivalence
point by changing the color of the solution . The transition
from acidic color to basic color depends on the pH . This
color change is not practically so abrupt but takes an
interval of nearly two pH units . Color change interval
varies with different indicators , so that one has to select
an indicator that distinctly changes the color at the
appropriate pH level .
In neutralization reaction :
H3+O + OH -
2H2O
This reaction denotes the neutralization of a strong acid
and strong base . From this reaction we can say that acid
is any substance that supplies hydronium ions [H+] or any
substance that consumes the hydroxide ions [OH -] ; while
the base is any substance that supplies hydroxide ions or
consumes the hydronium ions [H3O+] . This is the core of
the Arrhenius concept towards the acid – base theory.
In non-aqueous solutions , this definition is not enough
and has to modified to cope with certain reactions
involving Complexometric reactions . According to
Arrhenius , acids furnish hydronium ions in aqueous
solutions and can be stated in the following form .
HA + H2O H3+O + A - (2)
The equilibrium constant for the dissociation of the acid HA
will be:
Ka =
Assuming the concentration of H2O so large with respect
63. to other species , we can consider it . Therefore the
dissociation constant of the acid will be:
Ka = (3)
We also know that in aqueous solution the dissociation
constant of water ,Kw , is
Kw = [H3+O][OH -] ;
the dissociation constant of base is,
A -+ H2O HA + OH
–
Kb = (4)
From equation 3 and 4 , Ka =
Substituting for the value of Kb as , Ka = , and Kb
=
So Ka Kb = Kw , and pKa + pKb = Kw where pK
= - log k
In aqueous solutions , strong acids and strong bases
ionize completely so it becomes much easier to calculate
both hydrogen and hydroxyl ions from the stoichiometric
reaction between the acid and the base. This quantitative
process is clearly shown by using pH meter in which
stepwise addition of definite volume of the acid to the
base is recorded and the following pH curve is obtained .
Fig.1
From these curves , the equivalence point can easily be
determined . If the titration is performed without pH meter
, visual indicator is used to determine the equivalence
point .
Different acid-base titrations need different visual
indicators and choice of the indicator is determined by the
nature of the reacting acids and bases .
64. In strong acid-base titrations , the equivalence point fall in
between pH 3.3 and 10.7 , in that case phenolphthalein will
be the suitable indicator , see table ( 2 ) . The concentration
of the reacting species has an effect on the inflection
point. The more the concentration the sharper the inflection
point .
Experimental procedure of acid – base titrations are
conducted in this chapter. Before beginning detailed
experiment , we have to have well prepared standardized
solutions , these solutions are usually prepared from certain
substance that carry the properties of primary standard
solution . These substances include , Na2CO3 , H2C2O4 ,
H2SO4 , H3BO3 etc .
Hydrochloric acid is commonly used titrant ; although
different standard solutions can be prepared , it is more
convenient to prepare HCl of approximate normality and
standardize with a primary standard like sodium carbonate ,
Na2CO3 . The reaction takes two steps :
(a) Na2CO3 + HCl NaHCO3 + NaCl
Phenolphthalein indicator
(b) NaHCO3 + HCl CO2 + NaCl + H2O
Methyl orange indicator
Na2CO3 + 2HCl CO2 + 2 NaCl + H2O
Visual Indicators:
The main purpose of the titration is the determination of
the amount of acid or base present in any given solution .
This is achieved by locating the equivalence point which
gives us the stoichiometric amount of an acid or base
chemically equivalent to known amount of a base or an
acid .
Indicators are weak organic acids or bases that maintain a
color change in definite pH value . The pH value in which
color change takes place varies with different indicators
65. therefore we can select an indicator which exhibits the
color change at pH close to that obtained at the
equivalence point. We mentioned that the change from acid
color to alkaline color is not abrupt but small interval of
about two pH units involved. Considering undissociated
acid indicator as (HIn) , and undissociated base as (InOH)
and both having different colors from their ions , the
equilibria in aqueous solution will be :
HIn H + + In- and InOH
OH - + In -
By applying the law of mass action and considering the activity
coefficient as one
(constant),
Kin = and [H +] = =
this equation shows that the actual color change of the
indicator is directly related to the hydrogen-ion
concentration . Applying the definition of pH , the equation
can be written as ,
pH = - log + pKin
For weak base indicator, [OH -] = x Kn , we know
that [OH -] =
Substituting for OH -, [H+] = .
Considering acidic form of an indicator as Ina and basic form as
Inb, the equilibrium constant is expressed as :
Ina H+ + Inb , KIn = , and [H+] =
x KIn
Taking the negative logarithm , pH = pKIn + log .
Considering this above equation , the acidic color limit will
be :
pH = pKIn - log , in which pH
= pKIn – 1
the corresponding alkaline limit will be :
pH = pKIn - log , in which pH
= pKIn + 1
66. therefore the color change interval will be pH = pKIn
Table (2), shows different indicators with their pH range ,
color change and their preparations.
Indicator
pH - range
Acid color
Base color
Preparation
Methyl orange
3.1 – 4.4
Red
Yellow
0.01% in H2O (Na-form)
Methyl red
4.8 – 6.0
Red
Yellow
0.02g in 60ml EtOH + 40ml H2O
Phenolphthalein
8.0 – 9.6
Colorless
Red
0.05g in 50ml EtOH + 50ml H2O
Bromo cresol purple
5.2 – 6.8
Yellow
Purple
0.1g in 18.5ml of 0.01M NaOH + 225ml H2O
P-nitrophenol
5.6 – 7.6
Colorless
67. yellow
0.1% in H2O
Bromothymol blue
6.0 – 7.6
Yellow
Blue
0.1g in 16ml of 0.01M NaOH + 225ml H2O
Phenol red
6.4 – 8.0
Yellow
Red
0.1g in 28.2ml of 0.01M NaOH + 225ml H2O
Neutral red
6.8 – 8.0
Red
Orange
0.01g in 50ml EtOH 50ml H2O
Cresol purple
7.6 – 9.2
Yellow
Purple
0.1g in 50ml EtOH + 50ml H2O
Selected Experiments
· Acid – base titrations.
Experiment (1–1), standardization of HCl against sodium
carbonate (Na2CO3).
· Titration apparatus
A. Burette (50 ml)
B. Burette Stand
C. Pipette (10 ml)
D. Conical Flask (150 or 250 ml)
E. Methyl orange indicator solution
· Required
68. Solution
s.
A. 0.1N potassium hydrogen phthalate (20.3 g/liter)
B. 0.1N anhydrous sodium carbonate (Na2CO3 5.3 g/liter ) .
C. 0.1N HCl ( 8.4ml/liter )
D. 0.1N NaOH ( 4.0 g/liter) .
Procedure: Take 10 ml of the prepared sodium carbonate
into 250 ml conical flask and add 2-3 drops of methyl
orange ( yellow color will be formed ) . Use unit-volume or
graduated pipette in the process .
Fill the burette with the hydrochloric acid ; adjust the
volume reading exactly and record it . Remove any traces
of air inside the solution . Begin the titration by adding
the HCl from the burette onto the carbonate solution
carefully and systematically until the end point is close
enough . Then make the addition drop-wise until the last
drop turns the solution persistent pink color ; and record
the values . Repeat the experiment several times until the
values are close together within 2-3 units .
69. Take the average and report as follows:
Initial burette reading
Final burette reading
Vol. reacted, Titer (ml)
0.00
12.20
12.20
12.20
23.50
11.30
23.50
34.20
11.30
Average titer = 11.60
We know that one equivalent of any substance reacts
practically or theoretically with one equivalent of the
other. Therefore number of equivalents of Na2CO3 reacted =
Number of equivalents of HCl reacted. So that, 0.01-liter x
0.1 equiv./liter = 0.0116-liter x NHCl
NHCl = x 0.086N , which is the concentration of the
standardized hydrochloric acid .
Experiment (1-2) :
Standardization of sodium hydroxide against potassium
70. hydrogen phthalate(A.R), or against sulfuric acid (optional).
Reagents:
A. Titration apparatus
B. 0.1N NaOH
C. 0.1N Potassium hydrogen phthalate (C8H5KO4) or 0.1N
H2SO4
D. Phenolphthalein indicator (0.05 g in 100 ml water/ethanol
(1:1) .
Procedure: Transfer 10ml NaOH with a pipette into 250ml
conical flask . Rinse the walls of the flask with distilled
water . Fill the burette with the sulfuric acid or with the
potassium hydrogen phthalate and adjust the volume to
specific reading . Begin to add the acid into the base until
the end point gets closer ( the color is about to disappear )
. Then begin to add drop-wise until the last drop turns
the solution colorless . Tabulate the data and perform the
necessary calculations as experiment (1-1) .
Experiment (1 - 3). Determination of calcium carbonate in an
impure sample (back titration technique).
Calcium carbonate is an insoluble salt , so definite amount
71. of an excess acid is added to dissolve. After the formation
of a clear solution, the acid is back titrated with a base. The
sample could be limestone, marble, egg shell etc.
Requirements :
A. Titration apparatus
B. Standard 1M HCl
C. Standardized 0.1N NaOH
D. Methyl orange indicator (0.01 g – soluble M.O in water ).
E. Powdered sample
Weigh accurately 1- 1.5 g . of the carbonate sample and
transfer it to 400ml beaker. Add about 20 – 25 ml distilled
water, then add 40 ml of 1M HCl; when the effervescence
ceases completely , transfer the contents into a 100ml
volumetric flask and dilute it to the mark so that you can
establish your own dilution factors . Titrate definite
aliquots of the diluted solution with sodium hydroxide
using methyl orange indicator. calculate the amount of
calcium carbonate in the sample
CaCO3 + 2HCl CaCl2 + H2O + CO2
1 mole 2moles
M.wtCaCO3 = 100
Calculations : 100 x 100 x = % by weight of CaCO3 .
72. Experiment (1-4): Determination of both carbonate and
hydroxide in a mixture" commercial caustic soda analysis."
Requirements:
A. Commercial sodium hydroxide
B. Standard 0.1N HCl
C. 0.04M BaCl2 solution
D. Methyl orange and phenolphthalein indicators
In this experiment , total alkali is determined (both , CO32-
and OH-) by titrating a portion of the mixture solution
with standard acid .The other portion is added an excess
of barium chloride solution to precipitate all the carbonate
, and without filtering the solution is titrated with standard
acid ; this will give the hydroxide volume . Subtracting the
second volume from the previous titration volume , will
give the volume of the acid that neutralized the carbonate
.
BaCl2 + Na2CO3 BaCO3 + 2NaCl
V = volume of the acid using methyl orange ( total alkali )
v = volume of the acid due to phenolphthalein ( hydroxide )
then,
V – 2(V-v) = the volume of the acid that neutralized the
hydroxide. and 2(V – v) is the volume of the acid that
neutralized the carbonate .
73. Procedure: Prepare commercial sodium hydroxide solution by
accurately weighing about 2.5 g and transfer it quickly into
500ml volumetric flask , dissolve it well with deionized
water and fill it up to the mark . Titrate 25ml portion of
this solution with standard o.1N HCl using 3drops of methyl
orange as an indicator . Repeat the process several times
until you get almost the same reading .
Warm another 25ml portion up to 75oC and add 0.04 M
BaCl2 solution (quantitatively from burette in a slight
excess ). Cool the solution , add 2drops of phenolphthalein,
and titrate with 0.1M HCl with constant stirring until the
solution turns colorless . Repeat the process several times
to get acceptable values .
Keep in mind that 1ml of 1M HCl 0.04 g NaOH , and
1ml of 1M HCl 0.053 g Na2CO3 .
Experiment (1-5):Determination of aspirin in aspirin tablet
Aspirin is an organic compound with carboxylic and an
ester group . By hydrolyzing with an alkali , salt of weak
acid is formed which can be neutralized with a dilute
acid .
74. C6H4(CO2H)OOCCH3 + NaOH/H2O
C6H4(OH)CO2Na + CH3COONa
Aspirin (acetylsalicylic acid)
sodium salicylate sodium acetate
The alkali sodium acetate is titrated with dilute sulfuric
acid , using phenol red or phenolphthalein as an indicator .
Requirements:
A. Titration apparatus
B. 1M sodium hydroxide
C. 0.05M sulfuric acid
D. Phenol red or phenolphthalein indicator
E. Aspirin tablets
Exact number of aspirin tablets (1.5 – 2.0 g) are accurately
weighed and transferred into a conical flask . Add 25ml of
1M NaOH and 25ml of distilled water. Simmer the mixture
gently for about 10 – 15 minutes to hydrolyze the tablets.
After cooling the mixture , transfer quantitatively to 250ml
volumetric flask . Dilute to the mark and mix well by
repeated inversions. Titrate aliquots of the reaction mixture
with standard 0.05M H2SO4 using phenol red or
phenolphthalein .
· Calculate the weight of acetylsalicylic acid .
· Molecular wt. of acetylsalicylic acid = 180.16.
75. · 1mol of H2SO4 1mol of acetylsalicylic acid.
Experiment (1-6):Determination of available nitrogen in
fertilizers.
If ammonium salts are treated with an excess of strong
alkali like sodium hydroxide ammonia gas is liberated. The
gas is then trapped in excess of dilute acid which can be
back titrated with dilute sodium hydroxide.
NH4Cl + NaOH heat NH3 + NaCl + H2O , or
NH4+ + OH- NH3 + H2O
Keep in mind that nitrogen compounds are essential nutrients in
most fertilizers.
Requirements:
A. Distillation assembly
B. Titration apparatus
C. Standard 0.1N sodium hydroxide
D. Standard 0.1N hydrochloric acid
E. Methyl orange indicator
F. Fertilizer sample (or NH4Cl salt)
Procedure: The distillation apparatus is set up in such a
way that the receiver adapter is immersed below the
76. surface of the hydrochloric acid .Weigh accurately definite
amount of fertilizer (or NH4Cl salt) , not more than 2.0 g ,
into 50ml distillation flask . Add 25ml of 2N NaOH
solution , few boiling chips and quickly connect to the
distillation apparatus. Heat the contents gently to get
smooth boiling. Avoid any sucking back from the receiver
adapter during boiling . Continue the distillation process
until about 10ml of the original solution remains ( 30 – 40
min) .
When the distillation is over , disconnect the apparatus
from top before removing the Bunsen burner or any other
heating system . Wash any residues in the condenser and
receiver adapter into a 150ml conical flask and titrate
against .0.1N NaOH using 3drops of methyl orange
indicator.
Calculate:
A. The weight of ammonia distilled.
B. Percent of available nitrogen in the fertilizer.
· Precipitation Titrations
Precipitation titrations are among the oldest analytical methods
employed in chemical analysis. Up to now they are applied in
certain volumetric analysis such as the determination of
silver , chlorides , bromides , iodides and thiocyanates. In this
method , certain organic indicators are used ; these
77. indicators have the property of adsorption or desorption on
the solid materials formed during the precipitation . This
adsorption and desorption process takes places near the
equivalence point accompanied by change in the color ; the
procedure is called Fagan’s method as an honour for Polish
scientist Kazimierz Fagan’s ; among these indicators are
fluorescein and its derivatives . Since most of these
procedures involve the application of silver nitrate
solutions they are called argentometric methods.
We have mentioned that the most important precipitation
titration utilizes silver nitrate as the reagent for the
process ; therefore in these titrations , we will theoretically
confine our discussions to argentometric reactions .Before
we launch the practical aspect of this titration , let us
consider certain important concepts relating the solubility
of the salt AgCl which forms during the titration process.
Silver chloride is sparingly soluble in water, and considering
its (AgCl) saturated solution the solubility equilibrium will
be represented as:
AgCl(s) Ag (aq) +
Cl -(aq)
Ksp =
This is an example of heterogeneous equilibrium so the
78. concentration of the solid part (AgCl) remains constant in
the solution and can be taken as unity (1) so that :
Ksp = [Ag+][Cl-]
This molar product of Ag+ and Cl - at equilibrium is
called solubility product . In expressing the solubility
product of the ions involved , the stoichiometric
coefficients are raised .
Ag2S 2Ag+ + S2- ,
Ksp = [Ag+]2[S2-]
Table 2.2 , shows the solubility product (Ksp) of certain
slightly soluble salts at 25oC .
It must be understood that the smaller the value , the less
79. soluble salt in water . We can determine the Ksp from the
molar concentration at equilibrium and vice versa . Ksp is
comparatively easy to calculate with respect to other
equilibrium calculations .
Example 1.
An aqueous saturated solution of silver carbonate was
analysed and found to contain 8 mg of the salt dissolved
in 250 ml. Calculate the Ksp of the Ag2CO3 .
