This document discusses the physico-chemical properties of proteins, including their physical and chemical properties. It describes proteins' ability to dissociate depending on pH, their optical activity, solubility which depends on factors like pH and salt concentration, and their ability to form foams and stabilize foams through adsorption at gas-liquid interfaces. It also discusses proteins' hydration, swelling power in water, and ability to form gels through polymeric networks or aggregate dispersions.
1. Many factors affect the rate of enzyme-catalyzed reactions including substrate concentration, inhibitors, pH, temperature, pressure, and water content.
2. Enzyme activity is highest at its optimal pH and temperature, and decreases significantly above and below these values. It is also affected by the concentrations of inhibitors and activators.
3. Environmental factors like temperature, pressure, and water content can irreversibly denature enzymes and decrease their activity. Careful control of these factors allows for inhibition of undesirable enzyme reactions in food processing and storage.
This document discusses protein reactions that occur during food processing. It covers both enzyme-catalyzed and chemical reactions that proteins undergo, including proteolytic enzymes like serine and cysteine endopeptidases. Specific modifications are described, such as the Maillard reaction and changes induced by heat, pH, oxidation. Controlling these reactions through processing conditions and enzymes is important for food properties and safety.
This document provides an overview of peptides. It defines peptides as short chains of amino acids linked by peptide bonds. Peptides are distinguished from proteins based on their smaller size, typically containing fewer than 50 amino acid units. The document discusses peptide bond formation, characteristics of peptide bonds, classes of peptides, physical properties, examples of individual peptides, food-derived peptides with biological activity, and applications of peptides in molecular biology.
Enzymes have many applications in food processing. Examples include:
1. Glucose oxidase and catalase are used to remove oxygen and glucose from foods to prevent browning and extend shelf life.
2. Amylases are used in brewing and baking to break down starches.
3. Proteinases or peptidases are used in cheese production, meat tenderizing, and improving dough properties.
4. Immobilized enzymes can be reused, making them more economical for continuous processes.
The document discusses the structure of proteins at different levels:
- Primary structure refers to the amino acid sequence in the polypeptide chain. Secondary structure involves hydrogen bonding that forms alpha helices or beta pleated sheets. Tertiary structure describes the overall 3D shape of the folded polypeptide chain. Quaternary structure involves the interactions between multiple polypeptide subunits. The document outlines the forces that stabilize protein structures such as disulfide bonds, hydrogen bonding, and hydrophobic interactions. Proteins are classified based on their composition, which can include modifications like glycoproteins, lipoproteins, or metal-binding groups.
Proteins contribute significantly to the physical properties of foods, allowing them to build or stabilize gels, foams, doughs, emulsions, and fibrillar structures. Proteins act as foam-forming and foam-stabilizing agents by forming flexible films around gas bubbles that decrease surface tension. The stability of foams, emulsions, and gels depends on factors like the protein's ability to diffuse, denature, and associate at interfaces. Proteins can also increase viscosity, bind flavors, form dough networks, and exhibit antioxidant properties depending on their amino acid composition and structure.
Properties of proteins (Chemistry of Proteins (Part - IV)Ashok Katta
This document discusses various properties and reactions of proteins. It describes how proteins between 1-100nm behave as colloids and can sink in water due to their size and mass. It also explains how plasma proteins exert osmotic pressure, with albumin contributing most of the pressure due to its lower molecular weight. The document outlines factors that cause protein denaturation and precipitation, such as heat, acids, salts, metals and solvents. It provides examples of precipitation tests including heat coagulation, half/full salt saturation, and reactions with metals or alkaloids.
1. Many factors affect the rate of enzyme-catalyzed reactions including substrate concentration, inhibitors, pH, temperature, pressure, and water content.
2. Enzyme activity is highest at its optimal pH and temperature, and decreases significantly above and below these values. It is also affected by the concentrations of inhibitors and activators.
3. Environmental factors like temperature, pressure, and water content can irreversibly denature enzymes and decrease their activity. Careful control of these factors allows for inhibition of undesirable enzyme reactions in food processing and storage.
This document discusses protein reactions that occur during food processing. It covers both enzyme-catalyzed and chemical reactions that proteins undergo, including proteolytic enzymes like serine and cysteine endopeptidases. Specific modifications are described, such as the Maillard reaction and changes induced by heat, pH, oxidation. Controlling these reactions through processing conditions and enzymes is important for food properties and safety.
This document provides an overview of peptides. It defines peptides as short chains of amino acids linked by peptide bonds. Peptides are distinguished from proteins based on their smaller size, typically containing fewer than 50 amino acid units. The document discusses peptide bond formation, characteristics of peptide bonds, classes of peptides, physical properties, examples of individual peptides, food-derived peptides with biological activity, and applications of peptides in molecular biology.
Enzymes have many applications in food processing. Examples include:
1. Glucose oxidase and catalase are used to remove oxygen and glucose from foods to prevent browning and extend shelf life.
2. Amylases are used in brewing and baking to break down starches.
3. Proteinases or peptidases are used in cheese production, meat tenderizing, and improving dough properties.
4. Immobilized enzymes can be reused, making them more economical for continuous processes.
The document discusses the structure of proteins at different levels:
- Primary structure refers to the amino acid sequence in the polypeptide chain. Secondary structure involves hydrogen bonding that forms alpha helices or beta pleated sheets. Tertiary structure describes the overall 3D shape of the folded polypeptide chain. Quaternary structure involves the interactions between multiple polypeptide subunits. The document outlines the forces that stabilize protein structures such as disulfide bonds, hydrogen bonding, and hydrophobic interactions. Proteins are classified based on their composition, which can include modifications like glycoproteins, lipoproteins, or metal-binding groups.
Proteins contribute significantly to the physical properties of foods, allowing them to build or stabilize gels, foams, doughs, emulsions, and fibrillar structures. Proteins act as foam-forming and foam-stabilizing agents by forming flexible films around gas bubbles that decrease surface tension. The stability of foams, emulsions, and gels depends on factors like the protein's ability to diffuse, denature, and associate at interfaces. Proteins can also increase viscosity, bind flavors, form dough networks, and exhibit antioxidant properties depending on their amino acid composition and structure.
Properties of proteins (Chemistry of Proteins (Part - IV)Ashok Katta
This document discusses various properties and reactions of proteins. It describes how proteins between 1-100nm behave as colloids and can sink in water due to their size and mass. It also explains how plasma proteins exert osmotic pressure, with albumin contributing most of the pressure due to its lower molecular weight. The document outlines factors that cause protein denaturation and precipitation, such as heat, acids, salts, metals and solvents. It provides examples of precipitation tests including heat coagulation, half/full salt saturation, and reactions with metals or alkaloids.
This document discusses reactions of proteins involved in food processing. It describes various enzyme-catalyzed reactions like those involving serine, cysteine, metallo and aspartic endopeptidases. It also discusses chemical and enzymatic modifications of proteins for food processing, including succinylation, reductive methylation, and disulfide bond reduction/reoxidation. The enzymatic plastein reaction is described which joins peptide fragments through peptide bonds. Overall, the document provides an overview of reactions and modifications that can change protein properties for uses in food processing.
Denaturation of protein involves the disruption and possible destruction of structures. Since denaturation reactions are not strong enough to break the peptide bond, the primary structure remains the same after a denaturation process. Denaturation disrupts the normal alpha –helix and beta sheets in a protein and uncoils it into a random shape.
This document discusses the physico-chemical properties of proteins under two main sections: physical properties and chemical reactions. The physical properties section describes 5 sub-properties: dissociation, optical activity, solubility/hydration/swelling, foam formation and stabilization, and emulsifying effect. The chemical reactions section lists 7 amino acid residues that proteins can undergo chemical modifications with: arginine, glutamic/aspartic acid, cystine, cysteine, methionine, histidine, and tyrosine. Protein properties and reactions are important for understanding protein structure, function, and applications in food processing.
This document provides an overview of drug metabolism and biotransformation. It defines biotransformation as the biochemical alteration of drugs or xenobiotics by enzymes. The liver is identified as the major site of biotransformation. Drug metabolism occurs in two phases - phase I involves reactions like oxidation, reduction and hydrolysis. Phase II involves conjugating reactions. Factors like enzyme induction and inhibition can influence the extent of drug metabolism. Cytochrome P450 enzymes and phase I and II enzymes involved in biotransformation are also discussed.
This document discusses drug metabolism and biotransformation. It describes how drugs are structurally modified inside the body through Phase I and Phase II metabolic pathways. Phase I metabolism involves oxidation, reduction and hydrolysis reactions by cytochrome P450 enzymes and flavin monooxygenases. This makes the drugs more hydrophilic but can also activate some drugs. Phase II conjugation reactions like glucuronidation and sulfation catalyzed by transferase enzymes further increases hydrophilicity and promotes excretion of drug metabolites. The liver is the major site of drug metabolism though other tissues also play a role. Enzyme induction and inhibition can impact drug metabolism.
The loss of native conformation brings about changes in specific properties characterizing the identity of proteins.
Bring changes in the proteins.
It makes peptide bonds more readily available for hydrolysis by proteolytic enzymes.
Protein solubility decreased (hydrophobic groups exposed out).
Biological properties (catalytic, hormonal) are lost.
Viscosity and optical rotation increases.
Proteins affect the sensory properties of food, i.e.,
appearance;
texture (sols, gels, foams, emulsions, extruded pieces);
colour (via browning reactions);
flavor (via browning reactions and sulphide elimination reactions, via proteolysis, and by entrapment and binding of both desirable and undesirable flavors).
The document discusses biotransformation, which refers to chemical alterations of drugs in the body that make them more polar and able to be eliminated. It covers major topics like the phases of biotransformation (Phase I involving reactions like oxidation and Phase II involving conjugation), sites of biotransformation mainly the liver, and classes of drug metabolizing enzymes involved like cytochromes P450. It provides examples of specific enzyme reactions and drug substrates. Overall it serves as a comprehensive overview of the process of biotransformation in the body.
Drug metabolism involves the chemical modification of drugs inside the body through enzymatic reactions. There are two main phases - in Phase I, functional groups are introduced onto the drug molecule through reactions like oxidation, reduction and hydrolysis, making the drug more polar and able to be eliminated. In Phase II, polar groups are conjugated onto the drug, like glucuronidation or sulfation, which allows the drug to be more readily excreted from the body. The major sites of drug metabolism are the liver, small intestine and kidneys, and it occurs through cytochrome P450 enzymes in the endoplasmic reticulum and cytosol of cells.
Drug metabolism involves converting lipophilic compounds into hydrophilic derivatives that can be readily excreted. This occurs mainly through oxidation, reduction and hydrolysis reactions in the liver and intestines (Phase I), followed by conjugation reactions that attach groups like glucuronic acid to facilitate excretion (Phase II). Many factors can influence an individual's drug metabolism, like age, species, genetics, sex, and interactions between drugs and foods that induce or inhibit metabolic enzymes. Understanding these metabolic pathways and factors is important for predicting drug interactions and toxicity.
This document discusses drug metabolism and biotransformation. It describes the two main phases:
1) Phase I reactions introduce functional groups like hydroxyl or carboxyl to make compounds more hydrophilic.
2) Phase II or conjugation reactions attach endogenous compounds like glucuronic acid or sulfate to phase I metabolites or parent compounds, forming water-soluble conjugated products that are pharmacologically inactive.
The document provides examples of oxidative, reductive, and hydrolytic phase I reactions and glucuronic acid, sulfate, amino acid, acetylation, and methylation phase II conjugations.
1. Metabolism, or biotransformation, is the process by which enzymes convert lipid-soluble compounds into water-soluble compounds so they can be excreted from the body.
2. The major site of drug metabolism is the liver, through phase I (functionalization) and phase II (conjugation) reactions. Phase I reactions involve oxidation, reduction, and hydrolysis, while phase II reactions conjugate compounds to make them more hydrophilic through glucuronidation, methylation, sulfation, and other processes.
3. Cytochrome P450 enzymes and UDP-glucuronyl transferases are among the most important enzyme families involved in drug metabolism. Metabolism can
Biotransformation involves the chemical alteration of drugs in the body through phase 1 and phase 2 reactions. Phase 1 reactions like oxidation, reduction and hydrolysis activate or expose functional groups on drugs. Phase 2 reactions like conjugation make drugs more polar and excretable. The liver is the primary site of biotransformation through cytochrome P450 enzymes and UDP-glucuronyltransferases. First pass metabolism can decrease oral bioavailability. Drug interactions can occur through enzyme induction, increasing metabolism of other drugs, or enzyme inhibition, decreasing metabolism of other drugs.
This document discusses drug metabolism and biotransformation. It begins by defining drug metabolism as the chemical conversion of a drug to another form. The document then explores the effects of biotransformation, including pharmacological inactivation or activation of drugs, and changes or no changes in pharmacological activity. Various pathways and factors that influence drug metabolism are examined, including phase I and phase II reactions as well as cytochrome P450 enzymes. The factors that can affect drug biotransformation rates like enzyme induction and inhibition are also summarized.
The document summarizes various processes involved in drug biotransformation and elimination from the body. It discusses two main phases - Phase I reactions which involve oxidation, reduction and hydrolysis to make drugs more polar. Phase II reactions then conjugate these products to endogenous moieties like glucuronic acid, sulfate or glutathione to facilitate excretion. Specific reactions in each phase like aromatic hydroxylation, carbonyl reduction, glucuronidation and acetylation are explained in detail.
Amino acid analysis and peptide mapping Likhith KLIKHITHK1
Amino Acid Analyzer is specifically configured system optimized for analysis of free amino acids.
PURPOSE:
Detection of presence of Amino acid in variety of biological samples, such as
extracellular and intracellular fluids
plant and animal tissues,
broths, and fruits
beverage juices
Detection of presence of hydrolyzed Amino acid, such as found in
protein, collagen, peptides, and processes foods.
Peptide mapping is an identity test for proteins, especially those
obtained by r-DNA technology. Peptide mapping is a comparative procedure because the information obtained, compared to a Reference Standard or Reference Material similarly treated, confirms the primary structure of the protein, is capable of detecting whether alterations in structure have occurred, and demonstrates process consistency and genetic stability. Peptide mapping refers to the identification of proteins using data from intact peptide masses. It is a powerful test that is capable of identifying single amino acid changes resulting from events such as errors in the reading of complementary DNA (cDNA) sequences or point mutations.
This document discusses drug metabolism. It defines metabolism as the network of chemical processes that maintain life. Drug metabolism occurs through various phases including oxidation, reduction, hydrolysis, and conjugation reactions. These reactions are catalyzed by enzymes like cytochrome P450 and occur mainly in the liver and intestines. The consequences of metabolism can include inactivation of drugs, production of active metabolites, or increased activity as in the case of prodrugs. Factors like genetic polymorphisms and drug interactions can impact the metabolism of drugs.
The document discusses drug metabolism and biotransformation in the liver. It notes that the liver uses metabolic enzymes to make nonpolar compounds more water soluble through oxidation, reduction, and hydrolysis reactions so they can be excreted in urine. These phase I reactions introduce or expose polar groups. Phase II then involves conjugating the metabolite to glucuronic acid, sulfate, or glycine for excretion. The major sites of these reactions are the microsomal and cytoplasmic enzymes in hepatic cells.
To invite someone to join your NHS network, log into www.networks.nhs.uk and go to your network page. From there, select the "Network admin tools" option and choose "Invite someone to join this network". Enter the invitee's email address and an optional message, then send the invitation. However, this only works if your network is open to all or visible to non-members, as private networks cannot be joined without approval from the network administrator.
The document discusses the levels of protein structure from primary to quaternary structure. It defines the primary structure as the amino acid sequence. Secondary structure forms from hydrogen bonding between amino acids and includes alpha helices and beta pleated sheets. Tertiary structure results from folding influenced by interactions between amino acid side chains. Quaternary structure occurs when multiple polypeptide chains interact to form a protein complex. Examples including hemoglobin and glyceraldehyde-3-phosphate dehydrogenase are provided to illustrate the different levels of structure.
This document discusses reactions of proteins involved in food processing. It describes various enzyme-catalyzed reactions like those involving serine, cysteine, metallo and aspartic endopeptidases. It also discusses chemical and enzymatic modifications of proteins for food processing, including succinylation, reductive methylation, and disulfide bond reduction/reoxidation. The enzymatic plastein reaction is described which joins peptide fragments through peptide bonds. Overall, the document provides an overview of reactions and modifications that can change protein properties for uses in food processing.
Denaturation of protein involves the disruption and possible destruction of structures. Since denaturation reactions are not strong enough to break the peptide bond, the primary structure remains the same after a denaturation process. Denaturation disrupts the normal alpha –helix and beta sheets in a protein and uncoils it into a random shape.
This document discusses the physico-chemical properties of proteins under two main sections: physical properties and chemical reactions. The physical properties section describes 5 sub-properties: dissociation, optical activity, solubility/hydration/swelling, foam formation and stabilization, and emulsifying effect. The chemical reactions section lists 7 amino acid residues that proteins can undergo chemical modifications with: arginine, glutamic/aspartic acid, cystine, cysteine, methionine, histidine, and tyrosine. Protein properties and reactions are important for understanding protein structure, function, and applications in food processing.
This document provides an overview of drug metabolism and biotransformation. It defines biotransformation as the biochemical alteration of drugs or xenobiotics by enzymes. The liver is identified as the major site of biotransformation. Drug metabolism occurs in two phases - phase I involves reactions like oxidation, reduction and hydrolysis. Phase II involves conjugating reactions. Factors like enzyme induction and inhibition can influence the extent of drug metabolism. Cytochrome P450 enzymes and phase I and II enzymes involved in biotransformation are also discussed.
This document discusses drug metabolism and biotransformation. It describes how drugs are structurally modified inside the body through Phase I and Phase II metabolic pathways. Phase I metabolism involves oxidation, reduction and hydrolysis reactions by cytochrome P450 enzymes and flavin monooxygenases. This makes the drugs more hydrophilic but can also activate some drugs. Phase II conjugation reactions like glucuronidation and sulfation catalyzed by transferase enzymes further increases hydrophilicity and promotes excretion of drug metabolites. The liver is the major site of drug metabolism though other tissues also play a role. Enzyme induction and inhibition can impact drug metabolism.
The loss of native conformation brings about changes in specific properties characterizing the identity of proteins.
Bring changes in the proteins.
It makes peptide bonds more readily available for hydrolysis by proteolytic enzymes.
Protein solubility decreased (hydrophobic groups exposed out).
Biological properties (catalytic, hormonal) are lost.
Viscosity and optical rotation increases.
Proteins affect the sensory properties of food, i.e.,
appearance;
texture (sols, gels, foams, emulsions, extruded pieces);
colour (via browning reactions);
flavor (via browning reactions and sulphide elimination reactions, via proteolysis, and by entrapment and binding of both desirable and undesirable flavors).
The document discusses biotransformation, which refers to chemical alterations of drugs in the body that make them more polar and able to be eliminated. It covers major topics like the phases of biotransformation (Phase I involving reactions like oxidation and Phase II involving conjugation), sites of biotransformation mainly the liver, and classes of drug metabolizing enzymes involved like cytochromes P450. It provides examples of specific enzyme reactions and drug substrates. Overall it serves as a comprehensive overview of the process of biotransformation in the body.
Drug metabolism involves the chemical modification of drugs inside the body through enzymatic reactions. There are two main phases - in Phase I, functional groups are introduced onto the drug molecule through reactions like oxidation, reduction and hydrolysis, making the drug more polar and able to be eliminated. In Phase II, polar groups are conjugated onto the drug, like glucuronidation or sulfation, which allows the drug to be more readily excreted from the body. The major sites of drug metabolism are the liver, small intestine and kidneys, and it occurs through cytochrome P450 enzymes in the endoplasmic reticulum and cytosol of cells.
Drug metabolism involves converting lipophilic compounds into hydrophilic derivatives that can be readily excreted. This occurs mainly through oxidation, reduction and hydrolysis reactions in the liver and intestines (Phase I), followed by conjugation reactions that attach groups like glucuronic acid to facilitate excretion (Phase II). Many factors can influence an individual's drug metabolism, like age, species, genetics, sex, and interactions between drugs and foods that induce or inhibit metabolic enzymes. Understanding these metabolic pathways and factors is important for predicting drug interactions and toxicity.
This document discusses drug metabolism and biotransformation. It describes the two main phases:
1) Phase I reactions introduce functional groups like hydroxyl or carboxyl to make compounds more hydrophilic.
2) Phase II or conjugation reactions attach endogenous compounds like glucuronic acid or sulfate to phase I metabolites or parent compounds, forming water-soluble conjugated products that are pharmacologically inactive.
The document provides examples of oxidative, reductive, and hydrolytic phase I reactions and glucuronic acid, sulfate, amino acid, acetylation, and methylation phase II conjugations.
1. Metabolism, or biotransformation, is the process by which enzymes convert lipid-soluble compounds into water-soluble compounds so they can be excreted from the body.
2. The major site of drug metabolism is the liver, through phase I (functionalization) and phase II (conjugation) reactions. Phase I reactions involve oxidation, reduction, and hydrolysis, while phase II reactions conjugate compounds to make them more hydrophilic through glucuronidation, methylation, sulfation, and other processes.
3. Cytochrome P450 enzymes and UDP-glucuronyl transferases are among the most important enzyme families involved in drug metabolism. Metabolism can
Biotransformation involves the chemical alteration of drugs in the body through phase 1 and phase 2 reactions. Phase 1 reactions like oxidation, reduction and hydrolysis activate or expose functional groups on drugs. Phase 2 reactions like conjugation make drugs more polar and excretable. The liver is the primary site of biotransformation through cytochrome P450 enzymes and UDP-glucuronyltransferases. First pass metabolism can decrease oral bioavailability. Drug interactions can occur through enzyme induction, increasing metabolism of other drugs, or enzyme inhibition, decreasing metabolism of other drugs.
This document discusses drug metabolism and biotransformation. It begins by defining drug metabolism as the chemical conversion of a drug to another form. The document then explores the effects of biotransformation, including pharmacological inactivation or activation of drugs, and changes or no changes in pharmacological activity. Various pathways and factors that influence drug metabolism are examined, including phase I and phase II reactions as well as cytochrome P450 enzymes. The factors that can affect drug biotransformation rates like enzyme induction and inhibition are also summarized.
The document summarizes various processes involved in drug biotransformation and elimination from the body. It discusses two main phases - Phase I reactions which involve oxidation, reduction and hydrolysis to make drugs more polar. Phase II reactions then conjugate these products to endogenous moieties like glucuronic acid, sulfate or glutathione to facilitate excretion. Specific reactions in each phase like aromatic hydroxylation, carbonyl reduction, glucuronidation and acetylation are explained in detail.
Amino acid analysis and peptide mapping Likhith KLIKHITHK1
Amino Acid Analyzer is specifically configured system optimized for analysis of free amino acids.
PURPOSE:
Detection of presence of Amino acid in variety of biological samples, such as
extracellular and intracellular fluids
plant and animal tissues,
broths, and fruits
beverage juices
Detection of presence of hydrolyzed Amino acid, such as found in
protein, collagen, peptides, and processes foods.
Peptide mapping is an identity test for proteins, especially those
obtained by r-DNA technology. Peptide mapping is a comparative procedure because the information obtained, compared to a Reference Standard or Reference Material similarly treated, confirms the primary structure of the protein, is capable of detecting whether alterations in structure have occurred, and demonstrates process consistency and genetic stability. Peptide mapping refers to the identification of proteins using data from intact peptide masses. It is a powerful test that is capable of identifying single amino acid changes resulting from events such as errors in the reading of complementary DNA (cDNA) sequences or point mutations.
This document discusses drug metabolism. It defines metabolism as the network of chemical processes that maintain life. Drug metabolism occurs through various phases including oxidation, reduction, hydrolysis, and conjugation reactions. These reactions are catalyzed by enzymes like cytochrome P450 and occur mainly in the liver and intestines. The consequences of metabolism can include inactivation of drugs, production of active metabolites, or increased activity as in the case of prodrugs. Factors like genetic polymorphisms and drug interactions can impact the metabolism of drugs.
The document discusses drug metabolism and biotransformation in the liver. It notes that the liver uses metabolic enzymes to make nonpolar compounds more water soluble through oxidation, reduction, and hydrolysis reactions so they can be excreted in urine. These phase I reactions introduce or expose polar groups. Phase II then involves conjugating the metabolite to glucuronic acid, sulfate, or glycine for excretion. The major sites of these reactions are the microsomal and cytoplasmic enzymes in hepatic cells.
To invite someone to join your NHS network, log into www.networks.nhs.uk and go to your network page. From there, select the "Network admin tools" option and choose "Invite someone to join this network". Enter the invitee's email address and an optional message, then send the invitation. However, this only works if your network is open to all or visible to non-members, as private networks cannot be joined without approval from the network administrator.
The document discusses the levels of protein structure from primary to quaternary structure. It defines the primary structure as the amino acid sequence. Secondary structure forms from hydrogen bonding between amino acids and includes alpha helices and beta pleated sheets. Tertiary structure results from folding influenced by interactions between amino acid side chains. Quaternary structure occurs when multiple polypeptide chains interact to form a protein complex. Examples including hemoglobin and glyceraldehyde-3-phosphate dehydrogenase are provided to illustrate the different levels of structure.
Proteins are composed of amino acids and play many essential roles in the body. They have four levels of structure: primary, secondary, tertiary, and quaternary. The primary structure is the amino acid sequence, secondary involves hydrogen bonding into shapes like alpha helices and beta sheets, tertiary is the 3D folding of these structures, and quaternary involves the assembly of multiple protein subunits. Proteins serve as enzymes, hormones, antibodies, and structures. They undergo synthesis from amino acids and breakdown through catabolism. Disorders can occur if amino acid metabolism is disrupted.
This document discusses the properties and characteristics of amino acids. It covers their ionic properties, isoelectric points, optical activity, solubility, UV absorption, and various chemical reactions including esterification, acylation, alkylation, reactions with carbonyl compounds, and reactions involving functional groups like cysteine and methionine. It notes that amino acids are important in developing flavors and aromas in foods during high-temperature cooking methods like frying and baking.
The document is an exam for a course on infectious diseases of pet animals. It contains two questions asking about the epidemiology, diagnosis, and control of fading kitten syndrome, infectious causes of jaundice in cats, and canine hemorrhagic gastroenteritis. It also contains a second question about the line of treatment and control methods for feline respiratory disease complex, infectious feline military dermatitis, infectious tracheobronchitis in a German shepherd puppy, and adult-onset red mange in a mastiff bitch. The exam is for 1 hour and contains a total of 11.5 marks.
This document provides a course exam for diseases of pets (internal medicine). It lists 7 multiple choice questions covering various internal medical conditions in dogs and cats. The questions cover gastrointestinal disorders, esophageal and gastric disorders in dogs, congestive heart failure in dogs, chronic and acute renal failure, feline urological syndrome, and allergic skin conditions. Students are instructed to answer 5 of the 7 questions in the 1 hour exam.
Eggs provide a unique source of balanced nutrition. They are inexpensive, easy to prepare, and contain high-quality protein, vitamins, minerals, and fats. The formation of an egg involves the yolk being deposited in the oviduct and slowly passing down, gaining layers of albumen, membranes, and finally the shell over approximately 25 hours. The color of the shell, albumen, and yolk depend on the hen's diet and breed but do not impact the egg's nutritional value or cooking properties.
Whiplash es una película de 2014 dirigida por Damien Chazelle sobre un joven baterista llamado Andrew que asiste a una escuela de música en Nueva York donde es sometido a un entrenamiento brutal por su profesor Terence Fletcher para alcanzar la excelencia. La película sigue el viaje de Andrew para convertirse en un gran baterista a pesar de la intimidación de Fletcher.
This document provides an overview of various parasitic, viral, and bacterial infectious diseases that can affect dogs and cats. It contains images and descriptions of the causative agents of these diseases, including various parasites like roundworms, tapeworms, fleas, ticks, protozoa, fungi that cause ringworm, and viruses and bacteria that cause diseases like rabies, parvovirus, leptospirosis, and brucellosis. The document serves as a reference for the infectious agents that can sicken dogs and cats and the diseases they can cause.
Las ciencias sociales estudian el comportamiento y las interacciones de los seres humanos. Se clasifican en ciencias relacionadas con la interacción social, el sistema cognitivo humano y la evolución de las sociedades. Estas ciencias forman parte de la vida diaria y nos ayudan a tomar decisiones mediante el conocimiento de la realidad social. El método científico y el razonamiento lógico son las mejores formas de analizar esta realidad social.
Edible eggs can deteriorate quickly after laying if not stored properly. The key factors that affect egg quality are temperature, humidity, and handling. As eggs age, chemical and microbial changes occur. The air cell enlarges, the white thins and spreads out, and the yolk shifts and flattens. Microorganisms like bacteria and mold can cause rotting. Proper storage below 4°C and 70-80% humidity helps maintain freshness. Eggs are graded based on interior and exterior quality standards.
The document summarizes the structure of proteins at different levels:
- Primary structure is the specific sequence of amino acids in the protein backbone.
- Secondary structure describes segments of the backbone chain forming regular structures like alpha helices or beta pleated sheets.
- Tertiary structure is the overall 3D shape of the protein formed by interactions between amino acid side chains.
- Quaternary structure refers to proteins with multiple polypeptide chains interacting to form a complex.
La música en la primera mitad del S.XIXgusagalindo
La primera mitad del siglo XIX en Europa estuvo marcada por revoluciones liberales, el desarrollo de la Revolución Industrial y cambios sociales y culturales. Artísticamente, el Romanticismo se caracterizó por exaltar las pasiones individuales, la naturaleza, lo nacionalista y lo irracional sobre la razón. En la música, los compositores buscaron nuevas formas para expresar estos ideales románticos.
Este examen de historia sobre las civilizaciones maya y azteca consta de 10 secciones con preguntas de selección múltiple, términos pareados, completar, analizar imágenes y explicar conceptos. El examen evalúa los conocimientos de los estudiantes sobre la organización política, social y económica de estas civilizaciones precolombinas, así como sus logros culturales y técnicas agrícolas. El examen es individual y los estudiantes cuentan con 90 minutos para completarlo.
Patricia Boillaud, directrice de la DIRECCTE 92, nous a présenté hier, 16 mars 2017, sa feuille de route. Elle a longuement parlé de la garantie jeune et nous a sollicité comme marraines/parrains de promo ( environ 10 jeunes).
- The document discusses the pop singer Ariana Grande, listing some of her notable roles and hit songs such as "The Way", "Problem", "Break Free", and "Dangerous Woman".
- It also provides a brief physical description of Ariana Grande and asks the reader questions about the song "Santa Tell Me" by Ariana Grande, asking why they like the song, how it makes them feel, and when they like to listen to it.
- The favorite quoted lyric from the song is "Be my fire in the cold."
Protein and peptide drug delivery system (PPDDS)Sagar Savale
Protein and Peptide drug delivery system are the Novel drug Delivery
System. Proteins and peptides are the most abundant components of
biological cells. They exist functioning such as enzymes, hormones, structural element and immunoglobulin.
This document discusses stability problems and prevention strategies for proteins and peptides used in drug delivery systems. It describes how protein structure, including primary, secondary, tertiary, and quaternary levels can impact stability. Physical stability problems like denaturation from changes in solvent, pH, temperature and adsorption are explained. Chemical stability issues such as deamidation, oxidation, and reduction are also outlined. Methods to prevent various stability problems involving controlling solvents, pH, temperature, and use of stabilizing agents are presented.
Proteins are the most abundant and functionally diverse molecules in living systems. They perform essential functions like structure, movement, transport, defense, and regulation of processes. Proteins are classified based on their chemical properties, functions, and nutritional importance. Some major classifications include structural, enzymatic, transport, and storage proteins. Proteins can be precipitated through various means like heat denaturation, dehydration using alcohol, increasing salt concentrations, and reactions with heavy metals or alkaloids. Precipitation tests are used to separate and identify proteins.
Denaturation is the process by which proteins lose their native 3D structure and become biologically inactive. It can be caused by heat, chemicals, or other physical stresses. This disrupts the weak bonds and interactions that give proteins their shape. Specifically, denaturation involves the loss of secondary, tertiary, and quaternary structure through disruption of hydrogen bonds, hydrophobic interactions, and other forces. While the primary structure remains intact, the changes in 3D structure lead to altered properties and loss of biological function. Common denaturing agents include heat, acids, bases, organic solvents, and detergents which act by various mechanisms to disrupt protein structure.
Denaturation is the process by which proteins lose their native 3D structure and become biologically inactive. It occurs when weak bonds within a protein are disrupted, causing it to unfold. This unfolded state exposes hydrophobic amino acids to water. While the primary structure remains intact, secondary, tertiary and quaternary structures are lost. Common denaturants include heat, acids, bases, organic solvents, detergents and reducing agents. Denaturation is often irreversible and results in a loss of enzymatic activity and increased susceptibility to digestion.
1) Myosin has a minimum water holding capacity at its isoelectric point due to having no net charge, causing it to aggregate. When exposed to low salt concentrations, the isoelectric point shifts to a lower pH, further reducing the water holding capacity.
2) At its isoelectric point, the positive and negative charges on myosin proteins are equal, causing them to be attracted to each other and squeeze out water. Low salt concentrations exacerbate this effect by further shielding the charges.
3) Several amino acids in myosin are ionizable and can change protonation states depending on pH, shifting the overall charge on the protein and thus its isoelectric point.
Proteins are complex organic compounds composed of amino acids linked by peptide bonds. They come in many forms and have a wide diversity of functions. Proteins can be classified based on their structure, composition, solubility and functions. The main types include simple proteins like albumins and globulins, conjugated proteins which combine with non-protein groups, and derived proteins formed by hydrolysis of other proteins. Proteins play critical roles in the body as enzymes, structures, nutrients, and more.
Proteins are large, complex molecules that play crucial roles in the structure, function, and regulation of cells and organisms. Their functional properties arise from their specific three-dimensional structures, which are dictated by the sequence of amino acids in their chains. Here is a brief overview of the functional properties of proteins:
1. **Enzymatic Activity:** Many proteins act as enzymes, facilitating and catalyzing biochemical reactions within cells. Enzymes are involved in processes such as metabolism, DNA replication, and cellular signaling.
2. **Structural Support:** Proteins provide structural support to cells and tissues. Examples include the structural proteins collagen and keratin, which contribute to the strength and elasticity of connective tissues and hair, respectively.
3. **Transportation:** Proteins function as carriers and transporters, aiding in the movement of substances across cell membranes or within the bloodstream. Hemoglobin, for instance, transports oxygen in red blood cells.
4. **Cellular Signaling:** Signaling proteins, such as hormones and receptors, play a crucial role in transmitting signals within and between cells. These signals regulate various physiological processes and responses.
5. **Immune Defense:** Antibodies are proteins that form a key component of the immune system, recognizing and neutralizing foreign substances like bacteria and viruses.
6. **Motion and Contractility:** Proteins, like actin and myosin, are essential for muscle contraction and cellular movement. They interact to enable the contraction and relaxation of muscles, as well as the movement of cellular structures.
7. **Regulation of Gene Expression:** Transcription factors and other regulatory proteins control the expression of genes. They influence when and to what extent genes are turned on or off, thereby regulating cellular processes.
8. **Storage and Nutrient Reserves:** Some proteins serve as storage molecules, holding essential nutrients for later use. Examples include the storage proteins found in seeds, such as albumin and globulin.
9. **pH Regulation:** Buffering proteins help maintain the pH balance within cells and biological fluids, ensuring optimal conditions for enzymatic activity and other biochemical processes.
10. **Cell Adhesion:** Proteins play a role in cell adhesion, helping cells stick together to form tissues and organs. Cadherins, for instance, are proteins involved in cell-to-cell adhesion.
The diversity of protein functions is immense, reflecting the wide range of structures and biochemical activities that proteins can exhibit. The specific function of a protein is intricately linked to its structure, and any alterations in the protein's structure can lead to functional changes or loss of activity.
Effect of physical parameters on the properties of PROTEINSNeeraj Kumar
Proteins are composed of chains of amino acids that are linked together by peptide bonds. The amino acid composition determines a protein's properties. There are four levels of protein structure - primary, secondary, tertiary, and quaternary. The primary structure is the amino acid sequence. Secondary structure involves hydrogen bonding that forms alpha helices and beta sheets. Tertiary structure describes the three-dimensional folding of the polypeptide chain. Quaternary structure results from interactions between subunits in multimeric proteins.
This document discusses protein structure and folding. It explains that proteins fold into unique three-dimensional structures that are determined by their amino acid sequences. The folding process is driven by various weak interactions, especially hydrophobic interactions between amino acid side chains in the protein interior. While many conformations are possible, proteins predominantly adopt conformations that maximize these stabilizing interactions under biological conditions.
1. The document discusses various topics related to proteins and peptides, including what proteins are, their properties, classification, metabolism, and some protein-related disorders.
2. Key points include that proteins are composed of amino acids and are essential for human life, occurring in all cells. They can be classified based on their structure as globular, fibrous or membrane proteins.
3. Protein metabolism involves breaking down proteins through catabolism and building new proteins through anabolism. The urea cycle is involved in detoxifying ammonia produced from amino acid catabolism.
4. Some protein-related disorders discussed are maple syrup urine disease, Gaucher disease, kwashiorkor, and
This document provides information on protein structure and functions. It discusses that proteins are polymers made of amino acids and perform many important functions in the body, including structural support, enzymatic reactions, transport, regulation, contraction, storage, and defense. It describes the four levels of protein structure - primary, secondary, tertiary, and quaternary. The document also discusses properties of proteins like solubility and isoelectric point. It explains that denaturation involves loss of structure but not primary sequence, and lists various physical and chemical agents that can cause protein denaturation, such as temperature, pH, organic solvents, and heavy metals.
This document discusses various functional properties of proteins important in food systems, including emulsification, hydration, viscosity, gelation, texturizability, foaming, and emulsification. It explains how protein solubility, size, structure, and interactions with other components influence these properties. Specific examples are given of proteins that demonstrate different functionalities like thickening, water binding, and foam formation.
Protein denaturation, mechanism, causes, denaturation at interfaces,denaturation at different protein structures level, agents of protein denaturation, advantages and disadvantages of protein denaturation
This document provides an overview of protein and peptide delivery systems. It begins with an introduction to proteins, peptides, and their structures. It then discusses the physicochemical properties and instability issues of proteins and peptides, highlighting reasons for the need of protein and peptide drug delivery systems. The document outlines some advantages of these systems and barriers to protein delivery such as enzymatic barriers and intestinal epithelial barriers. Overall, the document provides a high-level introduction to protein and peptide delivery focusing on structures, properties, challenges, and the need for delivery systems to overcome instability issues.
This document discusses the use of gelatin in wine fining. It provides background on the basic chemistry of proteins and gelatin structure. Gelatin works by forming complexes between polyphenols in wine and gelatin proteins, as well as between natural wine proteins and gelatin. The isoelectric point of gelatin is more important than bloom strength in determining fining performance. While European data shows low bloom gelatins are best, South African experiments found no difference between 100-275 bloom gelatins, so economics determine choice. Very high molecular weight "superfine" gelatin adds insoluble fining like egg albumin.
Biological Molecules ( I and a group of friends )Daisy Sowah
Biology projectwork.please download to view more efficiently because there are A LOT of transitions and animations to consider before viewing ( it looks like pictures rest on the text because the text flies onto the screen, moves away and the pictures fall in )
Stability studies of proteins and peptides.SULABH910
This document discusses stability studies of proteins and peptides. It covers both chemical and physical degradation mechanisms and factors that influence degradation rates. Chemical degradation includes deamidation, racemization, hydrolysis, disulfide formation, oxidation, and cross-linking. Physical degradation involves changes in structure like denaturation, aggregation, adsorption, and precipitation. Degradation rates depend on factors like pH, temperature, moisture content, and excipients. Kinetics are often first-order and follow Arrhenius behavior, allowing prediction of long-term stability from accelerated studies. Understanding degradation mechanisms is key to developing stable protein and peptide drug formulations.
The document provides information about proteins including their introduction, chemical nature, physical properties, structure, classification, and functions. Some key points:
- Proteins are macromolecules composed of amino acid chains that serve important structural and functional roles in the body.
- They have complex hierarchical structures ranging from primary sequences to quaternary arrangements and take on globular or fibrous shapes.
- Proteins can be classified based on their shape, composition, solubility, and biological function. This includes categories like enzymes, structural proteins, and transport proteins.
- In addition to providing structure, proteins regulate body chemistry through roles as hormones, antibodies, and contractile proteins involved in muscle movement.
1) The document discusses food proteins and enzymes, their importance in biological systems, and their various functions and sources.
2) Proteins are made up of amino acids and play many critical roles including as enzymes, hormones, antibodies, and structural components.
3) The document covers the classification of amino acids, sources of food proteins like meat and dairy, and the roles of enzymes in catalyzing biochemical reactions.
Mahua, Madhuca longifolia (Koenig) (Synonyms, Madhuca indica Gmelin; Family, Sapotaceae), is a large, shady, deciduous tree dotting much of the central Indian landscape, both wild and cultivated. The tree is valued for its flowers, fruits, seeds and timber. The buttercup fruit-seeds, generally ellipsoidally shaped (Figure 1). Madhuca longifolia fruit is valued for its seed which yield high quantity of fat (ca. 50%), commercially known as mahua butter or mowrah butter, and it has many edible and medicinal applications. The butter is of significant commercial importance in India and is used for both edible and cosmetic applications. Mowrah Butter is a yellowish-white butter with a mild odor. The butter is solid at room temperature, but melts readily on contact with the skin. Besides its edible and medicinal uses, Madhuca longifolia fats can also be utilized in the manufacture of laundry soaps and lubricants. Data about mowrah butter are very few and there are not reports in literature about detailed composition of mowrah fat. Recently, in our lab mowrah butter was subjected to detailed and comprehensive analyses to obtain informative profile about the chemical nature of mowrah butter (1). The antiradical action of mowrah butter with also compared extra virgin olive oil. The results will be important as an indication of the potentially nutraceutical and economical utility of mowrah butter as a new source of edible fats.
Oil Recovery from Enzymatically-treated Goldenberry (Physalis peruviana L...Mohamed Hassanien
Fruit processing industry produce a large amount of agro-waste products which are a rich source of dietary fibre, protein and oil. Goldenberry (Physalis peruviana L.) is one of the most promising fruits and many interesting functional products anticipated to be developed from it [1, 2]. The pomace (seeds and skins) represent a large portion of the waste generated during juice processing (ca. 27.4% of fruit weight). To date, there has been no report on the by-products of goldenberry as well as the aqueous extraction of these by-products. This work was done to study the effects of several processing factors on enzyme-aided aqueous extraction of oil from goldenberry pomace and to verify the applicability of this innovative technology to goldenberry by-products. The main variables affecting the hydrolytic process should be enzyme concentration, hydrolysis time, particle size and moisture. The effect of these variables on the oil extractability from goldenberry agro-waste after juice processing was studied. The results provide important information for the industrial application of goldenberry. As a first step toward developing goldenberry as a commercial crop, the data obtained will be useful as an indication of the potentially economical utility of goldenberry as a source of edible oil.
This document discusses various enzymatic analytical methods used for food analysis, including substrate determination, enzyme activity determination, enzyme immunoassay, and polymerase chain reaction. Specifically, it covers:
1) Substrate determination methods like end-point assays that use coupled enzyme reactions to measure food constituents.
2) Determining enzyme activity in food to evaluate quality and optimize processes by measuring reaction rates under controlled conditions.
3) Enzyme immunoassays like ELISA that use antibody-antigen reactions and enzyme-labeled antigens to detect food compounds.
4) Polymerase chain reaction (PCR) which amplifies DNA for sensitive species identification and detecting genetically modified foods. PCR allows analysis of heat-treated foods where proteins
The document discusses factors that affect enzyme-catalyzed reactions, including substrate concentration, inhibitors, pH, temperature, and pressure. It explains how the reaction rate depends on substrate and enzyme concentrations and can be influenced by activators and inhibitors. It also describes how each enzyme has an optimal pH range and temperature, and discusses how temperature affects reaction rates, microbial growth rates, and thermal inactivation of enzymes.
The document discusses the structure of proteins at multiple levels, from primary to quaternary structure. It describes the primary structure as the amino acid sequence linked by peptide bonds. The secondary structure refers to local spatial arrangements, such as alpha helices and beta sheets, formed through hydrogen bonding between peptide bonds. Tertiary structure describes the overall 3D shape of the folded polypeptide chain. Quaternary structure applies to proteins made of multiple polypeptide subunits that assemble into an ordered structure. The document outlines various methods for determining protein structure, including amino acid sequencing and X-ray crystallography.
Peptides are short chains of amino acids linked by peptide bonds. They are distinguished from proteins by typically containing fewer than 50 amino acid units. Peptides are formed through condensation reactions between carboxyl and amino groups of separate amino acids, releasing a water molecule. Peptide bonds are rigid and planar, contributing to protein structure stability. Peptides serve many important biological functions and can be classified based on their production method, including through ribosomal translation, nonribosomal synthesis, and enzymatic digestion of proteins in foods. Bioactive peptides derived from food proteins can have beneficial effects like lowering blood pressure, cholesterol, and antimicrobial properties.
Implementation of International Educational ProgramMohamed Hassanien
This document discusses key elements for developing an international educational program, including a vision, mission, goals, values, student learning outcomes, and examples. It provides guidance on writing statements for each element and examples. The vision describes what the ideal future program would look like. The mission states the program's purpose and stakeholders. Goals are broad targets for the program. Values describe the program's principles. Student learning outcomes are specific statements of the knowledge and skills students will obtain.
Amino acids have several key properties:
1. They are amphoteric, taking on positive, negative, or neutral charges depending on pH. Their isoelectric point is when the net charge is neutral.
2. They have acidic and basic groups that allow them to undergo various chemical reactions like esterification, acylation, and reactions with carbonyl compounds.
3. When heated to high temperatures during cooking, amino acids can form mutagenic and potentially toxic compounds like acrylamide or heterocyclic amines. The Maillard reaction and Strecker degradation play important roles in these processes.
Proteins are complex polymers made up of amino acids linked by peptide bonds. They serve essential biological functions including catalyzing biochemical reactions as enzymes, transporting molecules, providing structure, and more. This document provides an introduction to food proteins and enzymes, discussing their importance, classification, sources, and functions. It defines proteins and enzymes, explains their roles in biological systems, and outlines the key amino acids that make up proteins.
Fast Antiradical Test for Monitoring Deep Fried OilsMohamed Hassanien
This document presents research on developing a fast antiradical test for monitoring deep fried oils. Deep frying is commonly used worldwide but causes physical and chemical changes to oils through oxidation. The researchers aimed to compare physicochemical parameters and antiradical performance of oils during frying. Oils were analyzed after frying at different time points. Strong correlations were found between total polar compounds, absorptivity at 232nm/270nm, and antiradical scavenging activity against DPPH radicals. This suggests antiradical testing could rapidly monitor oil quality changes during frying. The method is accurate, inexpensive, and independent of oil type.
Lipid Classes, Sterols and Tocopherols of Black cumin (Nigella sativa L.), Co...Mohamed Hassanien
The document analyzes and compares the lipid classes, fatty acid profiles, and triacylglycerol compositions of black cumin, coriander, and niger seed oils. Specifically:
- The neutral lipid fraction constitutes over 90% of the total lipids in each seed oil. Black cumin has the highest ratio of saturated to polyunsaturated fatty acids in its neutral lipid fraction.
- Coriander seed oil has the highest levels of the monounsaturated fatty acid petroselinic acid and contains more triolein and tripetroselinin than the other seed oils.
- Niger seed oil stands out for its high content of saturated fatty acids like palmitic acid and trip
Investigation on Lipid Composition of Exotic OilseedsMohamed Hassanien
This document summarizes the results of a study investigating the lipid composition and bioactive compounds of black cumin, coriander, and niger seed oils. High levels of oils were recovered from the seeds, making them suitable for vegetable oil production. The seed oils contained high amounts of essential fatty acids and antioxidants like tocopherols. Black cumin and coriander seed oils in particular could be produced and marketed as crude oils. The polar lipid fractions of the seeds oils showed antioxidant effects and could potentially be used as natural additives, lecithins, or in cosmetics. Further research is needed to understand how the seed oil compositions relate to biological effects and how processing may impact their structures and antioxidative
The document discusses preparing and testing novel phenolic-enriched lecithin formulations called phenolipids. It proposes that phenolipids could overcome oxidation issues with lecithin by binding phenolic compounds to phospholipids. The objectives are to prepare phenolipids using commercial lecithin and phenolics like quercetin, study their antioxidant properties in triolein models, and evaluate biological activities. Results show phenolipids have higher radical scavenging effects than individual compounds and protect triolein better against oxidation than lecithin or phenolics alone.
Travis Hills' Endeavors in Minnesota: Fostering Environmental and Economic Pr...Travis Hills MN
Travis Hills of Minnesota developed a method to convert waste into high-value dry fertilizer, significantly enriching soil quality. By providing farmers with a valuable resource derived from waste, Travis Hills helps enhance farm profitability while promoting environmental stewardship. Travis Hills' sustainable practices lead to cost savings and increased revenue for farmers by improving resource efficiency and reducing waste.
Current Ms word generated power point presentation covers major details about the micronuclei test. It's significance and assays to conduct it. It is used to detect the micronuclei formation inside the cells of nearly every multicellular organism. It's formation takes place during chromosomal sepration at metaphase.
Authoring a personal GPT for your research and practice: How we created the Q...Leonel Morgado
Thematic analysis in qualitative research is a time-consuming and systematic task, typically done using teams. Team members must ground their activities on common understandings of the major concepts underlying the thematic analysis, and define criteria for its development. However, conceptual misunderstandings, equivocations, and lack of adherence to criteria are challenges to the quality and speed of this process. Given the distributed and uncertain nature of this process, we wondered if the tasks in thematic analysis could be supported by readily available artificial intelligence chatbots. Our early efforts point to potential benefits: not just saving time in the coding process but better adherence to criteria and grounding, by increasing triangulation between humans and artificial intelligence. This tutorial will provide a description and demonstration of the process we followed, as two academic researchers, to develop a custom ChatGPT to assist with qualitative coding in the thematic data analysis process of immersive learning accounts in a survey of the academic literature: QUAL-E Immersive Learning Thematic Analysis Helper. In the hands-on time, participants will try out QUAL-E and develop their ideas for their own qualitative coding ChatGPT. Participants that have the paid ChatGPT Plus subscription can create a draft of their assistants. The organizers will provide course materials and slide deck that participants will be able to utilize to continue development of their custom GPT. The paid subscription to ChatGPT Plus is not required to participate in this workshop, just for trying out personal GPTs during it.
The debris of the ‘last major merger’ is dynamically youngSérgio Sacani
The Milky Way’s (MW) inner stellar halo contains an [Fe/H]-rich component with highly eccentric orbits, often referred to as the
‘last major merger.’ Hypotheses for the origin of this component include Gaia-Sausage/Enceladus (GSE), where the progenitor
collided with the MW proto-disc 8–11 Gyr ago, and the Virgo Radial Merger (VRM), where the progenitor collided with the
MW disc within the last 3 Gyr. These two scenarios make different predictions about observable structure in local phase space,
because the morphology of debris depends on how long it has had to phase mix. The recently identified phase-space folds in Gaia
DR3 have positive caustic velocities, making them fundamentally different than the phase-mixed chevrons found in simulations
at late times. Roughly 20 per cent of the stars in the prograde local stellar halo are associated with the observed caustics. Based
on a simple phase-mixing model, the observed number of caustics are consistent with a merger that occurred 1–2 Gyr ago.
We also compare the observed phase-space distribution to FIRE-2 Latte simulations of GSE-like mergers, using a quantitative
measurement of phase mixing (2D causticality). The observed local phase-space distribution best matches the simulated data
1–2 Gyr after collision, and certainly not later than 3 Gyr. This is further evidence that the progenitor of the ‘last major merger’
did not collide with the MW proto-disc at early times, as is thought for the GSE, but instead collided with the MW disc within
the last few Gyr, consistent with the body of work surrounding the VRM.
Or: Beyond linear.
Abstract: Equivariant neural networks are neural networks that incorporate symmetries. The nonlinear activation functions in these networks result in interesting nonlinear equivariant maps between simple representations, and motivate the key player of this talk: piecewise linear representation theory.
Disclaimer: No one is perfect, so please mind that there might be mistakes and typos.
dtubbenhauer@gmail.com
Corrected slides: dtubbenhauer.com/talks.html
Unlocking the mysteries of reproduction: Exploring fecundity and gonadosomati...AbdullaAlAsif1
The pygmy halfbeak Dermogenys colletei, is known for its viviparous nature, this presents an intriguing case of relatively low fecundity, raising questions about potential compensatory reproductive strategies employed by this species. Our study delves into the examination of fecundity and the Gonadosomatic Index (GSI) in the Pygmy Halfbeak, D. colletei (Meisner, 2001), an intriguing viviparous fish indigenous to Sarawak, Borneo. We hypothesize that the Pygmy halfbeak, D. colletei, may exhibit unique reproductive adaptations to offset its low fecundity, thus enhancing its survival and fitness. To address this, we conducted a comprehensive study utilizing 28 mature female specimens of D. colletei, carefully measuring fecundity and GSI to shed light on the reproductive adaptations of this species. Our findings reveal that D. colletei indeed exhibits low fecundity, with a mean of 16.76 ± 2.01, and a mean GSI of 12.83 ± 1.27, providing crucial insights into the reproductive mechanisms at play in this species. These results underscore the existence of unique reproductive strategies in D. colletei, enabling its adaptation and persistence in Borneo's diverse aquatic ecosystems, and call for further ecological research to elucidate these mechanisms. This study lends to a better understanding of viviparous fish in Borneo and contributes to the broader field of aquatic ecology, enhancing our knowledge of species adaptations to unique ecological challenges.
ESPP presentation to EU Waste Water Network, 4th June 2024 “EU policies driving nutrient removal and recycling
and the revised UWWTD (Urban Waste Water Treatment Directive)”
hematic appreciation test is a psychological assessment tool used to measure an individual's appreciation and understanding of specific themes or topics. This test helps to evaluate an individual's ability to connect different ideas and concepts within a given theme, as well as their overall comprehension and interpretation skills. The results of the test can provide valuable insights into an individual's cognitive abilities, creativity, and critical thinking skills
4. Physical Properties of Proteins
1- Dissociation
2- Optical Activity
3- Solubility, Hydration and Swelling
Power
4- Foam Formation and Foam Stabilization
5- Emulsifying Effect
5. 1- Dissociation
-Proteins, like amino acids, are amphoteric.
-Depending on pH, they can exist as polyvalent (cations, anions or
zwitter ions).
-Proteins differ in their α-carboxyl and α-amino groups.
-Since these groups are linked together by peptide bonds, the uptake or
release of protons is limited to free terminal groups. Therefore, most of
the dissociable functional groups are derived from side chains.
-The total charge of protein, which is the absolute sum of all positive and
negative charges, is differentiated from the so-called net charge which,
depending on the pH, may be positive, zero or negative.
-By definition the net charge is zero and the total charge is maximal at
the isoelectric point. Lowering or raising the pH tends to increase the net
charge towards its maximum, while the total charge always becomes less
than at the isolectric point.
6. -Since proteins interact not only with protons but also with other
ions, there is a further differentiation between an isoionic and an
isoelectric point.
-The isoionic point is defined as the pH of a protein solution at
infinite dilution, with no other ions present except for H+ and HO−.
Such a protein solution can be acquired by extensive dialysis (or
electro-dialysis) against water.
-The isoionic point is constant for a given substance while the
isoelectric point is variable depending on the ions present and
their concentration.
-In the presence of salts, i.e. when binding of anions is stronger
than that of cations, the isoelectric point is lower than the
isoionic point.
7. -The titration curve of β-
lactoglobulin at different ionic
strengths shows that the
isoelectric point of this protein, at
pH 5.18, is independent of the
salts present.
-At its isoelectric point a protein is
the least soluble and the most
likely to precipitate (isoelectric
precipitation) and is at its maximal
crystallization capacity.
-The viscosity of solubilized
proteins and the swelling power
of insoluble proteins are minimum
at the isoelectric point.
Titration curves for
β-lactoglobulin at various
ionic strengths (ω).
8. 2- Optical Activity
-The optical activity of proteins is due not only to
asymmetry of amino acids but also to the chirality
resulting from the arrangement of the peptide chain.
-Information on the conformation of proteins can be
obtained from a recording of the optical rotatory
dispersion (ORD) or the circular dichroism (CD),
especially in the range of peptide bond absorption
wavelengths (190–200 nm).
9. -The Cotton effectreveals quantitative informationon secondary structure.
-α-Helix or β-structure gives a negative Cotton effect, with absorption maxima
at 199 and 205 nm, respectively
-while a randomly coiled conformation shifts the maximum to shorter
wavelengths, i.e. results in a positive Cotton effect.
Cotton effect
A Polylysine α-helix (1, pH 11–11.5)
β-sheet structure (2, pH 11–11.3 and heated above 50 ◦ C) and
random coiled (3, pH 5–7).
B Ribonucleasewith 20% α-helix, 40% β-sheet structure and 40% random
coiled region.
A B
10. 3- Solubility, Hydration and Swelling Power
-Protein solubility is variable and is affected by the number of polar and
non-polar groups and their arrangement along the molecule.
-Generally, proteins are soluble only in strongly polar solvents such as
water, glycerol or formic acid.
-In a less polar solvent such as ethanol, proteins are rarely soluble
(prolamines).
-The solubility in water is dependent on pH and on salt concentration.
-If a protein has enough exposed hydrophobic groups at the isoelectric
point, it aggregates due to the lack of electrostatic repulsion via
intermolecular hydrophobic bonds, and (isoelectric) precipitation will
occur.
-If, on the other hand, intermolecular hydrophobic interactions are only
poorly developed, a protein will remain in solution even at isoelectric
point, due to hydration and stericthe repulsion.
11. -As a rule, salts have a two-fold effect on protein solubility.
At low concentrations they increase the solubility (“salting in”
effect) by suppressing the electrostatic protein-protein interaction
(binding forces).
-Protein solubility is decreased (“salting out” effect) at higher salt
concentrations due to the ion hydration tendency of the salts.
-Cations and anions in the presence of the same counter ion can
be arranged in the following orders (Hofmeister series) based on
their salting out effects:
K+ > Na+ > Li+ > NH+4 ; SO2
−4 > citrate−2> tratrate2−> acetate−> CI−>
NO−3 > Br−
-Multi-valent anions are more effective than mono-valent anions,
while di-valent cations are less effective than mono-valent
cations.
12. -Since proteins are polar substances, they are hydrated in water.
-The degree of hydration (g water of hydration/g protein) is variable.
It is 0.22 for ovalbumin (in ammonium sulfate), 0.8 for β-lactoglobulin
and 0.3 for hemoglobin.
-The swelling of insoluble proteins corresponds to the hydration of
soluble proteins in that insertion of water between the peptide chains
results in an increase in volume and other changes in the physical
properties of the protein.
-For example, the diameter of myofibrils increases to 2.5 times the
original value during rinsing with 1.0 mol/L NaCl, which corresponds to
a six-fold volume increase .
-The amount of water taken up by swelling can amount to a multiple of
the protein dry weight. For example, muscle tissue contains 3.5–3.6 g
water per g protein dry matter.
13. 4- Foam Formation and Foam Stabilization
-Foams are dispersions of gases in liquids.
-Proteins stabilize by forming flexible, cohesive films around the gas
bubbles. During impact, the protein is adsorbed at the interface via
hydrophobic areas; this is followed by partial unfolding (surface
denaturation).
-The reduction of surface tension caused by protein adsorption facilitates
the formation of new interfaces and further gas bubbles. The partially
unfolded proteins associate while forming stabilizing films.
-The more quickly a protein molecule diffuses into interfaces and the
more easily it is denatured there, the more it is able to foam. These
values in turn depend on the molecular mass, the surface hydrophobicity,
and the stability of the conformation.
-In several foods, proteins function as foam-forming and foam-stabilizing
components, for example in baked goods, sweets, desserts and beer.
14. 4- Foam Formation and Foam Stabilization
-This varies from one protein to another.
-Serum albumin foams very well, while egg albumin does
not.
-Protein mixtures such as egg white can be particularly
well suited. In that case, the globulins facilitate foam
formation.
-Ovomucin stabilizes the foam, egg albumin and
conalbumin allow its fixation through thermal
coagulation.
15. -Foams collapse because large gas bubbles grow at the expense of
smaller bubbles. That is why the stability of foam depends on the
strength of the protein film and its permeability for gases.
-Film strength depends on the adsorbed amount of protein and the
ability of the adsorbed molecules to associate.
-Surface denaturation generally releases additional amino acid side
chains which can enter into intermolecular interactions.
-The stronger the cross-linkage, the more stable the film.
-Since the smallest possible net charge promotes association, the pH of
the system should lie in the range of the isoelectric points of proteins
that participate in film formation.
In summary, the ideal foam-forming and foam-stabilizing protein is
characterized by a low molecular weight, high surface hydrophobicity,
good solubility, a small net charge in terms of the pH of the food, and
easy denaturability.
16. -Foams are destroyed by lipids and organic solvents such as higher
alcohols, which due to their hydrophobicity displace proteins from
the gas bubble surface without being able to form stable films
themselves.
-The foam-forming and foam-stabilizing characteristics of proteins
can be improved by chemical and physical modification. Thus, a
partial enzymatic hydrolysis leads to smaller, more quickly diffusing
molecules, better solubility, and the release of hydrophobic groups.
Disadvantages are the generally lower film stability and the loss of
thermal coagulability.
-The characteristics can also be improved by introducing charged or
neutral groups and by partial thermal denaturation (whey
proteins).
The addition of strongly alkaline proteins is being tested, which
apparently increases the association of protein in the films and
allows the foaming of fatty systems.
17. -Gels are disperse systems of at least two components in which the disperse
phase in the dispersant forms a cohesive network. They are characterized by
the lack of fluidity and elasticdeformability.
-Gels are placed between solutions, in which repulsive forces between
molecules and the disperse phase predominate, and precipitates, where strong
intermolecular interactions predominate.
-We differentiatebetweentwo types of gel
A-Polymericnetworks
B- Aggregateddispersions
although intermediate forms are found as well.
-Examples of polymeric networks are the gels formed by gelatin and
polysaccharides such as agarose. Characteristic for gels of this type is the low
polymer concentration(∼1%) as well as transparency and fine texture.
-Gel formation is caused by setting a certain pH, by adding certain ions, or by
heating/cooling. Since aggregation takes place mostly via intermolecular
hydrogen bonds which easily break when heated, polymeric networks are
thermo-reversible, i.e. the gels are formed when a solution cools, and they
melt again when it is heated.
18. -Examples of aggregated dispersions are the gels formed by globular proteins
after heating and denaturation.
-The thermal unfolding of the protein leads to the release of amino acid side
chains which may enter into intermolecular interactions. The subsequent
association occurs while small spherical aggregates form which combine into
linear strands whose interaction establishes the gel network.
-The degree of denaturation necessary to start aggregation seems to depend
on the protein. Since partial denaturation releases primarily hydrophobic
groups which results in the thermoplastic (thermo-irreversible) character of
this gel type, in contrast to the thermore-versible gel type stabilized by
hydrogenbonds.
-Thermoplasticgels do not liquefy when heated, but they can soften.
-In addition to hydrophobic bonds, disulfide bonds formed from released thiol
groups can also contribute to cross-linkage, as can intermolecular ionic bonds
between proteins with different isoelectric points in heterogeneous systems
(e.g. egg white).
19. -Gel formation can be improved by adding salt.
-The moderate increase in ionic strength increases interaction
between charged macro-molecules or molecule aggregates
through charge shielding without precipitation.
-An example is the heat coagulation of soybean curd tofu which
is promoted by calcium ions.
20. 5- Emulsifying Effect
-Emulsions are disperse systems of one or more immiscible liquids. They are
stabilized by emulsifiers-compounds which form interface films and thus prevent
the disperse phases from flowing together.
-Due to their amphipathic nature, proteins can stabilize o/w emulsions such as
milk. This property is made use of a large scale in foodpreparations.
-The adsorption of protein at the interface of an oil droplet is thermo-dynamically
favored because the hydrophobic amino acid residues can escape the hydrogen
bridge networkof the surrounding water molecules.
-In addition, contact of the protein with the oil droplet results in the displacement
of water molecules from the hydrophobicregions of the oil-water boundary layer.
-Therefore, the suitability of a protein as an emulsifier depends on the rate at
which it diffuses into the interface and on the deformability of its conformation
under the influence of interfacial tension(surface denaturation).
-The diffusion rate depends on the temperature and the molecular weight, which
in turn can be influenced by the pH and the ionic strength.
21. -The adsorbability depends on the exposure of hydrophilic and hydrophobic
groups and thus on the amino acid profile, as well as on the pH, the ion
strength and the temperature.
-The conformative stability depends in the amino acid composition, the
molecular weightand the intramolecular disulfide bonds.
-Therefore, protein with ideal qualities as an emulsifier for an oil-in-water
emulsionwould have
-a relativelylowmolecular weight,
-a balanced amino acid composition
-a good water solubility,
-a well-developedsurface hydrophobicity, and
-a relativelystable conformation.
-β-casein molecule meets these requirements because of less pronounced
secondary structures and no crosslinksdue to lack of SH groups.
-The non-polar “tail” of this flexible molecule is adsorbed by the oil phase of
the boundary layer and the polar “head”, which projects into the aqueous
medium, prevents coalescence.
-The solubility and emulsifying capacity of some proteins can be improved by
limitedenzymatichydrolysis.
24. -The chemical modification of protein is of importance for a
number of reasons.
A-It provides derivatives suitable for sequence analysis,
B-Identifies the reactive groups in active sites of an enzyme,
C-Enables the binding of protein to a carrier (protein
immobilization) and
D-Provides changes in protein properties which are important in
food processing.
-In contrast to free amino acids and except for the small number of
functional groups on the terminal amino acids, only the functional
groups on protein side chains are available for chemical reactions.
25. 1- Arginine Residue
-The arginine residue of proteins
reacts with α- or β-dicarbonyl
compounds to form cyclic
derivatives.
-The nitropyrimidine derivative
absorbs at 335 nm. The arginyl bond
of this derivative is not cleaved by
trypsin but it is cleaved in its
tetrahydro form, obtained by
reduction with NaBH4.
-In the reaction with benzil, an
iminoimidazolidone derivative is
obtained after a benzilic acid
rearrangement.
26. -Reaction of the arginine residue with 1,2-cyclohexanedione is
highly selective and proceeds under mild conditions.
-Regeneration of the arginine residue is again possible with
hydroxylamine.
27. 2- Glutamic and Aspartic Acid Residues
-These amino acid residues are usually esterified with methanolic HCl. There can
be side reactions, such as methanolysis of amide derivatives or N,O-acyl
migrationin serine or threonine residues
-Diazoacetamide reacts with a carboxyl group and also with the cysteine residue
- Amino acid esters or other similar nucleophilic compounds can be attached to a
carboxyl group of a proteinwith the help of carbodiimide
28. -Amidation is also possible by activating the carboxyl
group with an isooxazolium salt (Wood-ward reagent) to
an enolester and its conversion with an amine.
29. 3- Cystine Residue
-Cleavage of cystine is possible by a nucleophilicattack:
-The nucleophilic reactivity of the reagents decreases in the series:
hydride> phosphite> alkanethiol > aminoalkanethiol> thiophenol and cyanide>
sulfite> OH−> p-nitrophenol> thiosulfate > thiocyanate.
-Complete cleavage with sulfite requires that oxidative agents (Cu2+) be present
and that the pH be higher than 7:
30. -The resultant S-sulfo derivative is quite stable in neutral and acidic
media and is fairly soluble in water.
-The S-sulfo group can be eliminated with an excess of thiol
reagent.
-Cleavage of cystine residues with cyanides (nitriles) is of interest
since the thiocyanate formed in the reaction is cyclized to a 2-
iminothiazolidine derivative with cleavage of the N-acyl bond:
31. -This reaction can be used for the selective cleavage of peptide
chains.
-Initially, all the disulfide bridges are reduced, and then are
converted to mixed disulfides through reaction with 5,5-dithio-bis-
(2-nitro-benzoic acid). These mixed disulfides are then cleaved by
cyanide at pH 7.
-Electrophilic cleavage occurs with Ag+ and Hg+ or Hg2+ as follows:
-Electrophilic cleavage with H+ is possible only in strong acids (10
mol/L HCl).
32. 4- Cysteine Residue
-A number of alkylating agents yield derivatives which are stable under the
conditions for acidic hydrolysisof proteins.
-The reaction with ethylene imine giving an S-aminoethyl derivative and, hence,
an additional linkage positionin the proteinfor hydrolysis by trypsin.
-Iodoacetic acid, depending on the pH, can react with cysteine, methionine,
lysine and histidine residues
33. 4- Cysteine Residue
-The introduction of methyl groups is possible with methyl
iodide
or methyl isourea,
and the introduction of methylthio groups with
methylthiosulfonylmethane:
34. -Maleic acid anhydride
and methyl-p-nitro- benzene sulfonate are also alkylating agents
-A number of reagents make it possible to measure the thiol group
content spectrophotometrically.
35. 5- Methionine Residue
-Methionine residues are oxidized to sulfoxides with hydrogen peroxide.
-The sulfoxide can be reduced, regenerating methionine, using an excess
of thiol reagent.
-α-Halogen carboxylic acids and alkyl halogenides convert methionine into
sulfonium derivatives, from which methionine can be regenerated in an alkaline
medium with an excess of thiol reagent
36. 6- Histidine Residue
-Selective modification of histidine residues present on active sites of serine
proteinases is possible.
-Substrate analogues such as halogenated methyl ketones inactivate such
enzymes
for example:
-1-chloro-3-tosylamido-7-aminoheptan-2-oneinactivates trypsin and
-1-chloro-3-tosylamido-4-phenylbutan-2-one inactivates chymotrypsin
by N-alkylationof the histidine residue
37. 7- Tryptophan Residue
-N-Bromosuccinimide oxidizes the tryptophan side chain and also
tyrosine, histidine and cysteine
-The reaction is used for
A-The selective cleavage of peptide chains and
B- The spectrophotometric determination of tryptophan.
38. 8- Tyrosine Residue
-Selective acylation of tyrosine can occur with acetylimidazole as a
reagent
-Diazotized arsanilic acid reacts with tyrosine and with histidine,
lysine, tryptophan and arginine