Basic biochemistry of Carbohydrates suitable for undergraduate students.
This presentation has been started from the basics to enable easy understanding.
Lipid metabolism is the synthesis and degradation of lipids in cells.
It involves the breakdown or storage of fats for energy and the synthesis of structural and functional lipids, such as those involved in the construction of cell membranes.
In animals, these fats are obtained from food or synthesized by the liver.
Polysaccharide introduction, example, structure, starch, cellulose, chitin those structure and important functions and their presence in plants and animals, polysaccharide types based on functions and their composition , functions of polysaccharides , important images for relevant polysaccharides types, polysaccharide role in plants and animal cells. Starch - structure and functions, cellulose structure and functions, chitin - structure and functions
Lipid metabolism is the synthesis and degradation of lipids in cells.
It involves the breakdown or storage of fats for energy and the synthesis of structural and functional lipids, such as those involved in the construction of cell membranes.
In animals, these fats are obtained from food or synthesized by the liver.
Polysaccharide introduction, example, structure, starch, cellulose, chitin those structure and important functions and their presence in plants and animals, polysaccharide types based on functions and their composition , functions of polysaccharides , important images for relevant polysaccharides types, polysaccharide role in plants and animal cells. Starch - structure and functions, cellulose structure and functions, chitin - structure and functions
Sugar derivatives and reactions of monosaccharidesNamrata Chhabra
Reactions of monosaccharides, osazone formation, reduction, oxidation, reaction with acids and alkalies, ester formation and formation of amino sugars, amino sugar acids and deoxy sugars.
Carbohydrate
Polysaccharide
Homopolysaccarides
Different between Homopolysaccharides and Heteropolysaccharides
Example of Homopolysaccharides-
I) Starch
II) Glycogen
III) Cellulose
IV) Chitin
Application of Homopolysaccharides
Conclusion
reference
Any of a large group of compound (including sugar, starch and cellulose) which contain carbon, hydrogen, oxygen occur in food and living tissue can be and broken down to release energy in the body.
They are broadly classified into three classes based on the number of sugar unit:-
Monosaccharide
Oligosaccharide
Polysaccharide
Lipids Chemistry Structure & Function (More Detailed)hafizayyub
This presentation is for Medical students. It is more detailed explanation of Lipids including types and medical importance. It is made by Drs Charles Stephen and Dr Ayyub Patel
Lipid metabolism entails the oxidation of fatty acids to either generate energy or synthesize new lipids from smaller constituent molecules. Lipid metabolism is associated with carbohydrate metabolism, as products of glucose (such as acetyl CoA) can be converted into lipids.
Sugar derivatives and reactions of monosaccharidesNamrata Chhabra
Reactions of monosaccharides, osazone formation, reduction, oxidation, reaction with acids and alkalies, ester formation and formation of amino sugars, amino sugar acids and deoxy sugars.
Carbohydrate
Polysaccharide
Homopolysaccarides
Different between Homopolysaccharides and Heteropolysaccharides
Example of Homopolysaccharides-
I) Starch
II) Glycogen
III) Cellulose
IV) Chitin
Application of Homopolysaccharides
Conclusion
reference
Any of a large group of compound (including sugar, starch and cellulose) which contain carbon, hydrogen, oxygen occur in food and living tissue can be and broken down to release energy in the body.
They are broadly classified into three classes based on the number of sugar unit:-
Monosaccharide
Oligosaccharide
Polysaccharide
Lipids Chemistry Structure & Function (More Detailed)hafizayyub
This presentation is for Medical students. It is more detailed explanation of Lipids including types and medical importance. It is made by Drs Charles Stephen and Dr Ayyub Patel
Lipid metabolism entails the oxidation of fatty acids to either generate energy or synthesize new lipids from smaller constituent molecules. Lipid metabolism is associated with carbohydrate metabolism, as products of glucose (such as acetyl CoA) can be converted into lipids.
Biochemistry of carbohydrates_prepared_by_Drx_Raju_Yadav_2021RajYadav238
Carbohydrates, or carbs, are sugar molecules. Along with proteins and fats, carbohydrates are one of three main nutrients found in foods and drinks. Your body breaks down carbohydrates into glucose. Glucose, or blood sugar, is the main source of energy for your body's cells, tissues, and organs
Carbohydrates are polyhydroxy aldehydes or ketones or compounds derived from their hydrolysis.
includes- Definition, classification, examples, enantiomers, epimers, anomers, D and L isomers, ozasone testing, reducing and non reducing sugars, chemical tests and disease.
This presentation covers the details of floral development and its regulation. Aimed at the undergraduate and graduate students it helps easy understanding for the beginners.
Introduction to Chromosomal AberrationRiddhi Datta
This presentation is aimed at undergraduate and graduate students and covers details of the structural and numerical aberration of chromosomes. The presentation will help easy understanding of the beginners.
The presentation covers all the basic aspects of Kingdom Fungi including its salient features, cell wall structure, nutrition, spore forms, and reproduction.
The present ppt is covers all aspects of protein translation in bacteria as well as in eukaryotes. It also includes a brief introduction to ribosomes and tRNA which are among the key components of the translation machinery.
The presentation includes a description of three economically significant plant diseases: Late blight of Potato, Early blight of potato, Black stem rust of wheat and Citrus canker.
The presentation covers all details of the DNA structure for an easy understanding of Molecular biology students. It covers the details of DNA structure, its bonds as well as the different conformations.
The presentation covers the details of DNA replication starting from the basics of the replication process to the chemistry of DNA synthesis as well as the different models of replication.
This presentation covers the basics of gene cloning techniques starting from the REs, ligases and cloning vectors. It also covers some of the practical aspects of gene cloning to enable an in depth understanding.
The presentation is aimed for undergraduate students and covers the details of forest ecosystem, grassland ecosystem, desert ecosystem as well as aquatic ecosystems. It is suitable for compulsory environmental science course at undergraduate level. The content has been simplified for easy understanding of both science as well as humanities students.
Basic Cell cycle regulation suitable for undergraduate students.
This presentation has been started from the basics to enable easy understanding. It covers all the details of cell cycle regulation in yeast as well as higher eukaryotes.
Let's explore the nucleus, starting from the nuclear envelope to the molecular organization of chromatin. The presentation is suitable for undergraduate students and has been started from the basics to enable easy understanding. It covers details of nuclear envelope, nuclear pore complex, nucleolus as well as DNA packaging.
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.
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.
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.
A Strategic Approach: GenAI in EducationPeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
Macroeconomics- Movie Location
This will be used as part of your Personal Professional Portfolio once graded.
Objective:
Prepare a presentation or a paper using research, basic comparative analysis, data organization and application of economic information. You will make an informed assessment of an economic climate outside of the United States to accomplish an entertainment industry objective.
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.
Francesca Gottschalk - How can education support child empowerment.pptxEduSkills OECD
Francesca Gottschalk from the OECD’s Centre for Educational Research and Innovation presents at the Ask an Expert Webinar: How can education support child empowerment?
Welcome to TechSoup New Member Orientation and Q&A (May 2024).pdfTechSoup
In this webinar you will learn how your organization can access TechSoup's wide variety of product discount and donation programs. From hardware to software, we'll give you a tour of the tools available to help your nonprofit with productivity, collaboration, financial management, donor tracking, security, and more.
Synthetic Fiber Construction in lab .pptxPavel ( NSTU)
Synthetic fiber production is a fascinating and complex field that blends chemistry, engineering, and environmental science. By understanding these aspects, students can gain a comprehensive view of synthetic fiber production, its impact on society and the environment, and the potential for future innovations. Synthetic fibers play a crucial role in modern society, impacting various aspects of daily life, industry, and the environment. ynthetic fibers are integral to modern life, offering a range of benefits from cost-effectiveness and versatility to innovative applications and performance characteristics. While they pose environmental challenges, ongoing research and development aim to create more sustainable and eco-friendly alternatives. Understanding the importance of synthetic fibers helps in appreciating their role in the economy, industry, and daily life, while also emphasizing the need for sustainable practices and innovation.
2. • Carbohydrates are polyhydroxy aldehydes or ketones, or
substances that yield such compounds on hydrolysis.
• Many, but not all, carbohydrates have the empirical formula
(CH2O)n, [n≥3]; some also contain nitrogen, phosphorus, or sulfur.
• Carbohydrate literally means „hydrates of carbon‟.
• Carbohydrates are the most abundant biomolecules on Earth.
Dr. Riddhi Datta
3. • Certain carbohydrates (sugar and starch) are a dietary staple. Most abundant dietary source of
energy (4 cal/g)
• Insoluble carbohydrate polymers serve as structural and protective elements:
• in the cell walls of bacteria and plants
• in the connective tissues of animals
• lubricate skeletal joints
• participate in recognition and adhesion between cells
• Complex carbohydrate polymers that are covalently attached to proteins or lipids are called
glycoconjugates.
• act as signals that determine the intracellular location or metabolic fate of these hybrid
molecules
• Carbohydrates are precursors of many organic molecules (fats, amino acids, etc.)
• They serve as storage form of energy (Ex- Glycogen, Starch) Dr. Riddhi Datta
4. • The word “saccharide” is derived from the Greek „sakcharon’, meaning “sugar”
• Monosaccharides (simple sugars):
• Consist of a single polyhydroxy aldehyde or ketone unit.
• Oligosaccharides:
• consist of short chains of monosaccharide units, or residues (2-10), joined by characteristic
linkages called glycosidic bonds.
• Disaccharides:
• Consists of two monosaccharide units joined by glycosidic bond
• Ex- Sucrose (Glucose + Sucrose)
• Polysaccharides:
• sugar polymers containing more than 20 or so monosaccharide units, and some have hundreds
or thousands of units
• Ex- Cellulose, Glycogen
Dr. Riddhi Datta
5. • Simplest carbohydrates that can not be hydrolyzed to smaller carbohydrates.
• General chemical formula of unmodified monosaccharide is (C.H2O)n where n≥3
• Consist of a single polyhydroxy aldehyde or ketone unit.
• The most abundant monosaccharide in nature is the six-carbon sugar D-glucose.
• Monosaccharides of more than four carbons tend to have cyclic structures.
• Ex- Glyceraldehyde, Glucose, fructose, etc.
Dr. Riddhi Datta
6. • Classified according to 3 different characteristics:
• Placement of its carbonyl group
• Number of carbon atoms present
• Chiral handedness
Dr. Riddhi Datta
7. • Classes based on placement of its carbonyl group:
• ALDOSE: Functional group is an aldehyde group (-CHO)
• Ex- Glyceraldehyde, Glucose, etc
• KETOSE: Functional group is a keto group (>C=O)
• Ex- Dihydroxyacetone, Fructose, etc.
Dr. Riddhi Datta
8. • Classes based on number of carbon atoms present:
• Triose (3 C)
• Tetrose (4 C)
• Pentose (5 C)
• Hexose (6 C)
• Heptose (7 C)
Dr. Riddhi Datta
11. o Stereoisomers: Compounds that have same structural formulae but differ in their spatial
configuration.
o A carbon is said to be asymmetric (chiral) when it is attached to four different atoms or groups.
o The number of asymmetric carbon atoms (n) determines the possible isomers of a given
compound which is equal to 2n.
o Stereoisomerism is a characteristic feature of all sugars except Dihydroxyacetone.
o Example-
Glucose has 4 asymmetric carbon atoms. No. of isomers = 24 = 16
Glyceraldehyde has 1 asymmetric carbon atom. No. of isomers = 21 = 2
Dihydroxyacetone has no asymmetric carbon atoms. Hence, no isomer is possible.
Dr. Riddhi Datta
12. • Classes based on chiral handedness:
• D and L isomers: Assignment of D or L isomer is made
according to the orientation of the asymmetric carbon
atom furthest from the carbonyl group.
• In a standard Fischer projection if the hydroxyl group is on
the right, the molecule is D sugar, and if the hydroxyl
group is on the left, the molecule is L sugar.
• D-sugars are biologically more common.
Dr. Riddhi Datta
13. • Optical activity of sugars:
• It is the characteristic feature of compounds with asymmetric carbon atoms. When a beam of
polarized light is passed through a solution of an optical isomer, it will be rotated to either
the right or left.
• The terms dextrorotatory (+) and levorotarory (-) are used to compounds that respectively
rotate the plane of polarized light to the right or to the left.
• It may be noted that the D and L configurations of sugars are primarily based on the
structure, optical activities may be different.
• Racemic mixture: If D and L isomers are present in equal concentration, it is known as
racemic mixture or DL mixture. Racemic mixture does not exhibit any optical activity, since the
dextro- and levorotatory activities cancel each other.
Dr. Riddhi Datta
14. • Epimers
• If two monosaccharides differ from each other in their configuration around a single specific
carbon (other than anomeric carbon), they are referred to as epimers to each other.
• D-glucose and D-mannose differ only in the stereochemistry at C-2, are epimers.
• D-glucose and D-galactose which differ at C-4, are epimers.
Inter-conversions of epimers (eg.- glucose
to galactose and vice versa) is known as
epimerization and is catalyzed by a
group of enzymes called epimerases
Dr. Riddhi Datta
15. • In aqueous solution, aldotetroses and all monosaccharides with five or more carbon atoms in
the backbone occur predominantly as cyclic (ring) structures in which the carbonyl group has
formed a covalent bond with the oxygen of a hydroxyl group along the chain.
• The formation of these ring structures is the result of a general reaction between alcohols and
aldehydes or ketones to form derivatives called hemiacetals or hemiketals.
• These structures contain an additional asymmetric carbon atom and thus can exist in two
stereoisomeric forms.
Dr. Riddhi Datta
16. • D-glucose exists in solution as an intramolecular hemiacetal in which the free hydroxyl group
at C-5 has reacted with the aldehydic C-1, rendering the latter carbon asymmetric and
producing two stereoisomers, designated as α and β.
• These six-membered ring compounds are called pyranoses because they resemble the six
membered ring compound pyran.
• The systematic names for the two ring forms of D-glucose are α-D-glucopyranose and β-D-
glucopyranose.
• Only aldoses having five or more carbon atoms can form pyranose rings.
Dr. Riddhi Datta
17. • Aldohexoses also exist in cyclic forms having five membered rings, which,
because they resemble the five membered ring compound furan, are called
furanoses.
• The six-membered aldopyranose ring is much more stable than the aldofuranose
ring and predominates in aldohexose solutions.
Dr. Riddhi Datta
18. Anomers
• Isomeric forms of monosaccharides that differ only in their configuration about the hemiacetal or
hemiketal carbon atom are called anomers.
• The hemiacetal (or carbonyl) carbon atom is called the anomeric carbon.
• In case of α-anomer, the –OH group held by anomeric carbon is on the opposite side of the
–CH2OH group of the sugar ring. The opposite is true for β-anomers.
• The α- and β-anomers of D-glucose interconvert in aqueous solution by a process called
mutarotation.
• Thus, a solution of α-D-glucose and a solution of β-D-glucose eventually form identical
equilibrium mixtures having identical optical properties. This mixture consists of about one-third
α-D-glucose (36%), two-thirds β-D-glucose (63%), and very small amounts of the linear and
five-membered ring (glucofuranose) forms (1%).
α-D-glucose Equilibrium mixture β-D-glucose
+112.2° +52.7° +18.7°
Dr. Riddhi Datta
19. • Ketohexoses also occur in α and β anomeric forms.
• In these compounds the hydroxyl group at C-5 (or C-6) reacts with the keto
group at C-2, forming a furanose (or pyranose) ring containing a hemiketal
linkage.
• D-Fructose readily forms the furanose ring, the more common anomer of this
sugar in combined forms or in derivatives is D-fructofuranose.
• The specific optical rotation of fructose is -92° at equilibrium.
Dr. Riddhi Datta
20. • Monosaccharides can be oxidized by relatively mild oxidizing
agents such as ferric (Fe3+) or cupric (Cu2+).
• The carbonyl carbon is oxidized to a carboxyl group.
• Sugars capable of reducing ferric or cupric ion are called
reducing sugars. They have free aldehyde or ketone group
present in their structure.
• Ex- Glucose
• Sugars not capable of reducing ferric or cupric ion are called
non-reducing sugars. They do not have free aldehyde or ketone
group present in their structure.
• Ex- Sucrose
• This property is the basis of Fehling‟s reaction, a qualitative test
for the presence of reducing sugar.
Dr. Riddhi Datta
21. There are a number of sugar
derivatives in which a hydroxyl
group in the parent compound is
replaced with another substituent,
or a carbon atom is oxidized to a
carboxyl group.
• In amino sugars, an –NH2 group
replaces one of the -OH groups
in the parent
• hexose.
• Substitution of –H for –OH
produces a deoxy sugar.
• The acidic sugars contain a
carboxylate group, which confers
a negative charge at neutral pH.
Dr. Riddhi Datta
22. • Sugar acids: Oxidation of aldehyde or primary alcohol groups in the
monosaccharide results in sugar acids.
• The acidic sugars contain a carboxylate group, which confers a negative charge at
neutral pH.
• Examples:
• Gluconic acid is produced from glucose by oxidation of aldehyde group.
• Glucuronic acid is formed from glucose by oxidation of primary alcohol group (C6).
Dr. Riddhi Datta
23. • Amino sugars: When one or more hydroxyl groups of the monosaccharide are
replaced by amino groups, the products formed are called amino sugars.
• They are present as constituents of heteropolysaccharides.
• Examples:
• D-glucosamine
• D-galactosamine
• They are sometimes acetylated.
• Examples:
• N-acetyl-D-glucosamine
Dr. Riddhi Datta
24. • Deoxysugars: They contain one oxygen less than that of their parent molecule.
• The groups –CHOH and –CH2OH become –CH2 and –CH3 due to absence of one
oxygen atom.
• Examples:
• D-2-Deoxyribose
• L-Rhamnose
• L-Fucose
Dr. Riddhi Datta
25. • Sugar alcohols: Sugar alcohols (polyols) are produced by reduction of aldoses or
ketoses.
• Examples:
• Sorbitol from glucose
• Mannitol from mannose
• Alditols: The monosaccharides on reduction yield polyhydroxy alcohols known as
alditols.
• Examples:
• Ribitol (constituent of flavin coenzymes)
• Glycerol (Component of lipid)
• Xylitol (Sweetener used in sugarless gums and candies)
Dr. Riddhi Datta
26. • Disaccharides consist of two monosaccharides joined
covalently by an O-glycosidic bond, which is formed
when a hydroxyl group of one sugar reacts with the
anomeric carbon of the other.
• Example: maltose, lactose, and sucrose
• Glycosidic bonds are readily hydrolyzed by acid but
resist cleavage by base. Thus disaccharides can be
hydrolyzed to yield their free monosaccharide
components by boiling with dilute acid.
• N-glycosyl bonds join the anomeric carbon of a sugar
to a nitrogen atom in glycoproteins and nucleotides.
• General formula: Cn(H2O)n-1
Dr. Riddhi Datta
27. • The oxidation of a sugar‟s anomeric carbon by cupric or ferric ion (the reaction that
defines a reducing sugar) occurs only with the linear form, which exists in equilibrium
with the cyclic form(s).
• When the anomeric carbon is involved in a glycosidic bond, that sugar residue cannot
take the linear form and therefore becomes a non-reducing sugar.
• The end of a chain with a free anomeric carbon (one not involved in a glycosidic
bond) is commonly called the reducing end.
Dr. Riddhi Datta
28. • The disaccharide maltose contains
two D-glucose residues joined by a
glycosidic linkage between C-1 (the
anomeric carbon) of one glucose
residue and C-4 of the other.
• Because the disaccharide retains a
free anomeric carbon (C-1 of the
glucose residue on the right), maltose
is a reducing sugar.
Dr. Riddhi Datta
29. • By convention, the name describes the compound with its nonreducing end to the left.
• Give the configuration (α or β) at the anomeric carbon joining the first monosaccharide unit (on
the left) to the second.
• Name the nonreducing residue; to distinguish five- and six-membered ring structures, insert
“furano” or “pyrano” into the name.
• Indicate in parentheses the two carbon atoms joined by the glycosidic bond, with an arrow
connecting the two numbers; for example, (1 4) shows that C-1 of the first-named sugar residue
is joined to C-4 of the second.
• Name the second residue.
• If there is a third residue, describe the second glycosidic bond by the same conventions.
Short name:
Glc(α1 4)Glc
Dr. Riddhi Datta
30. • Sucrose (cane sugar) is made up of α-D-glucose and β-D-fructose linked by a glycosidic
bond (α1 β2). The reducing groups of glucose and fructose are involved in glycosidic
bond formation. Hence, sucrose is non-reducing sugar and it cannot form osazones.
• The systematic name of sucrose is α-D-glucopyranosyl-(1 2)- β-D-fructofuranoside. This
indicates:
• It is composed of two monosaccharides: glucose and fructose
• Ring type: Glucose is pyranose and fructose is furanose
• Linkage: oxygen on C1 of α-D-glucose is linked to C2 of β-D-fructose
• Suffix –oside and indicates that the anomeric carbon of both the monosaccharides
participate in glycosidic bond formation
• Sucrose is a major carbohydrate produced in
photosynthesis. It has the advantage as storage
and transport as its functional groups are held
together and are protected from oxidative attacks.
• Intestinal enzyme, sucrase hydrolyze sucrose to
glucose and fructose.
Dr. Riddhi Datta
31. Inversion of sucrose:
• Sucrose is dextrorotatory (+66.5°). But when hydrolyzed, it becomes levorotatory (-
28.2°). The process of change in optical rotation from dextrorotatory(+) to
levorotatory (-) is referred to as inversion. The hydrolyzed mixture of sucrose,
containing glucose and fructose, is known as invert sugar.
• Hydrolysis of sucrose by sucrase or dilute acid yeilds one molecule of glucose and
one molecule of fructose.
• Sucrose first splits into α-D-glucopyranose (+) and β-D-fructofuranose (+). But β-D-
fructofuranose is less stable and gets converted into β-D-fructopyranose (-). The
overall effect in the mixture becomes levorotatory (-).
Dr. Riddhi Datta
32. • Lactose (milk sugar) is composed of β-D-galactose and β-D-glucose held together by
β-(1 4) glycosidic bond.
• The anomeric carbon of C1 of glucose is free. Hence lactose exhibits reducing
properties and forms osazones (powder-puff or hedgehog shape).
• The systematic name is β-D-galactopyranosyl-(1 4) β-D-glucopyranose.
• It is hydrolyzed by intestinal enzyme lactase into glucose and galactose.
Dr. Riddhi Datta
33. • Maltose (malt sugar) is produced during digestion of starch by enzyme amylase.
• Maltose is composed of two α-D-glucose units held together by α(1 4)
glycosidic bond. A free aldehyde group is present on C1 of the second glucose
unit and hence maltose exhibits reducing properties and forms osazones
(sunflower shaped).
• It can be hydrolyzed by dilute acid or enzyme maltase.
• In isomaltose, the glucose units are held together by α(1 6) glycosidic bond.
Dr. Riddhi Datta
34. • It is identical to maltose, except that in it the linkage is β(1 4) glycosidic bond.
• It is formed during hydrolysis of cellulose.
• Raffinose (trisaccharides): Fructose+Galactose+Glucose
• Stachyose (Tetrasaccharide): Galactose+Galactose+Glucose+Fructose
• Verbascose (Pentasaccharide): Galactose+Galactose+Galactose+Glucose+Fructose
• It is identical to maltose, except that in it the linkage is (α1 α1) glycosidic bond.
• It is formed during hydrolysis of cellulose.
• It is a non-reducing sugar.
Dr. Riddhi Datta
35. • Carbohydrates containing repeating units (more than 10 units) of the monosaccharides or their
derivatives linked by glycosidic linkages are called polysaccharides.
• They are primarily concerned with 2 important functions:
• Structural role
• Storage of energy
• Polysaccharides can be linear or branched. The occurrence of branched polysaccharides is
due to the fact that glycosidic linkages can be formed at any one of the –OH groups of a
monosaccharide.
• Polysaccharides are of high molecular weight. They are usually tasteless (non-sugars) and
form colloids with water.
Dr. Riddhi Datta
36. Polysaccharides are of two types:
• Homopolysaccharides (Homoglycans): They,
on hydrolysis, yield only one type of
monosaccharide. They are named based on the
nature of the monosaccharide unit.
Example: Glucan (polymer of glucose),
Fructosan (polymer of fructose)
• Heteropolysaccharides (heteroglycans): They,
on hydrolysis, yield a mixture of a few types of
monosaccharide units or their derivatives.
Example: Peptidoglycan (polymer of N-
acetylglucosamine and N-acetylmuramic
acid residues)
Dr. Riddhi Datta
37. • Starch is the carbohydrate reserve of plants which is the most important dietary source for higher animals.
• Starch is a homopolysaccharide composed of D-glucose units held by glycosidic bonds.
• It is known as glucosan or glucan
• Starch consists of two polysaccharide components:
Water soluble amylose (15-20%)
Water insoluble amylopectin (80-85%)
• Chemically amylose is a long unbranched chain with 200-1000 D-glucose units held by (α1 4) glycosidic
linkage.
• Amylopectin is a branched chain with (α1 6) glycosidic bonds at the branching points and (α1 4)
glycosidic bonds everywhere else.
• Starches are hydrolyzed by amylases (pancreatic or salivary) to liberate dextrins and finally maltose and
glucose units. Amylase acts specifically on the (α1 4) glycosidic bonds.
Dr. Riddhi Datta
38. Dextrins
• These are the breakdown products of starch by the enzyme amylase or dilute acids.
• Starch is hydrolyzed through different dextrins and finally to maltose and glucose.
• The various intermediates (identified by iodine coloration) are soluble starch (blue),
amylodextrin (violet), erythrodextrin (red) and achrodextrin (no colour).
Inulin
• Inulin is a polymer of fructose.
• It occurs in dahlia bulbs, garlic, onion, etc.
• It is a low molecular weight (~ 5000) polysaccharide easily soluble in water.
• Inulin is not utilized by the body.
• It is used for assessing kidney function through measurement of glomerular filtration rate
(CFR).
Dr. Riddhi Datta
39. • Cellulose occurs extensively in plants and is totally absent in animals.
• Cellulose is composed of β-D-glucose units linked by β(1 4) glycosidic bonds.
• Cellulose can not be digested by mammals due to lack of the enzyme that cleaves β-glycosidic
bonds. Hydrolysis of cellulose yields a disaccharide, cellobiose, which is further broken down
to β-D-glucose units.
• It is a major constituent of fibers, the non-digestible carbohydrate.
Dr. Riddhi Datta
40. • Glycogen is the main storage polysaccharide of animal cells.
• Like amylopectin, glycogen is a polymer of (α1 4)-linked subunits of glucose, with
(α1 6)-linked branches, but glycogen is more extensively branched (on average, every 8 to
12 residues) and more compact than starch.
• Glycogen is especially abundant in the liver, it is also present in skeletal muscle.
Dr. Riddhi Datta
41. • Chitin is a linear homopolysaccharide composed of N-acetylglucosamine residues in β linkage.
• The only chemical difference from cellulose is the replacement of the hydroxyl group at C-2
with an acetylated amino group.
Dr. Riddhi Datta
42. • The rigid component of bacterial cell walls is a heteropolymer of alternating (β1 4)-linked
N-acetylglucosamine and N-acetylmuramic acid residues.
• The enzyme lysozyme kills bacteria by hydrolyzing the (β1 4) glycosidic bond between N-
acetylglucosamine and Nacetylmuramic acid.
Dr. Riddhi Datta