The document discusses amino acids and protein structure and function. It begins by describing how amino acids are linked by peptide bonds to form polypeptide chains and proteins. It then explains that amino acids can be essential, nonessential, or conditionally essential depending on whether they must be obtained from diet. The document also discusses protein structure, the uses of proteins in the body, and how the body breaks down and uses amino acids for energy or biosynthesis through various pathways.
The document discusses protein metabolism and degradation. It covers:
1) The processes of protein synthesis and catabolism as well as the digestion and absorption of dietary proteins in the stomach and intestines.
2) How cells degrade cellular proteins at different rates and have mechanisms to detect and remove damaged proteins using ubiquitin tags.
3) The ubiquitin tagging system involves three enzymes (E1, E2, E3) that attach ubiquitin to target proteins to mark them for destruction by the proteasome.
4) The fate of amino groups from degraded proteins, which are transferred to a-ketoglutarate by transamination reactions to form ammonium ions that enter metabolic pathways or are converted to
The document discusses amino acid metabolism. It begins by defining amino acids as derivatives of carboxylic acids with an amino group substitution. Amino acids are essential for building proteins and participate in many metabolic reactions. They are classified by the properties of their side chains. Protein digestion involves proteases in the stomach, pancreas, and small intestine that hydrolyze proteins into amino acids. Amino acids are absorbed into the blood and transported to tissues. Within cells, amino groups are transferred between amino acids and ketoacids in transamination reactions or removed as ammonia by deamination. The liver converts ammonia into less toxic urea via the urea cycle to prevent intoxication. Defects in the urea cycle can
The document discusses the urea cycle, which is a series of chemical reactions that occurs in the liver to convert ammonia into urea for excretion. There are five steps in the urea cycle, with two occurring in the mitochondria and three in the cytosol. The cycle involves ornithine, citrulline, argininosuccinate, and arginine as intermediates and uses two amino groups from ammonia and aspartate, along with carbon dioxide, to form urea. Disorders of the urea cycle can cause a dangerous buildup of ammonia in the blood called hyperammonemia.
Amino acids from dietary proteins and endogenous protein turnover can be used as an energy source in animals. Carnivores can obtain about 90% of their energy needs from amino acid oxidation after eating. Amino acids are broken down into common intermediate metabolites through transamination and deamination reactions. Excess amino groups are removed as ammonia, which is converted to less toxic urea primarily in the liver and excreted by the kidneys.
The document discusses the determination of the primary structure of proteins. It begins by explaining that proteins are composed of amino acid residues linked by peptide bonds to form a polypeptide chain. The primary structure refers to the specific sequence of amino acids in this chain. Mass spectrometry and tandem mass spectrometry techniques are used to analyze protein fragments obtained through enzymatic or chemical cleavage to determine the amino acid sequence and thereby elucidate the primary structure.
Structures and Functions of Biological Molecules Grade 11 Biology.pptxCjAndreaBeth
This ppt is actually my Performance Task but Bagyong Oddette came and unfortunately I didn't pass this ppt, hope a lot of youngsters being able to use this
The document discusses protein metabolism and degradation. It covers:
1) The processes of protein synthesis and catabolism as well as the digestion and absorption of dietary proteins in the stomach and intestines.
2) How cells degrade cellular proteins at different rates and have mechanisms to detect and remove damaged proteins using ubiquitin tags.
3) The ubiquitin tagging system involves three enzymes (E1, E2, E3) that attach ubiquitin to target proteins to mark them for destruction by the proteasome.
4) The fate of amino groups from degraded proteins, which are transferred to a-ketoglutarate by transamination reactions to form ammonium ions that enter metabolic pathways or are converted to
The document discusses amino acid metabolism. It begins by defining amino acids as derivatives of carboxylic acids with an amino group substitution. Amino acids are essential for building proteins and participate in many metabolic reactions. They are classified by the properties of their side chains. Protein digestion involves proteases in the stomach, pancreas, and small intestine that hydrolyze proteins into amino acids. Amino acids are absorbed into the blood and transported to tissues. Within cells, amino groups are transferred between amino acids and ketoacids in transamination reactions or removed as ammonia by deamination. The liver converts ammonia into less toxic urea via the urea cycle to prevent intoxication. Defects in the urea cycle can
The document discusses the urea cycle, which is a series of chemical reactions that occurs in the liver to convert ammonia into urea for excretion. There are five steps in the urea cycle, with two occurring in the mitochondria and three in the cytosol. The cycle involves ornithine, citrulline, argininosuccinate, and arginine as intermediates and uses two amino groups from ammonia and aspartate, along with carbon dioxide, to form urea. Disorders of the urea cycle can cause a dangerous buildup of ammonia in the blood called hyperammonemia.
Amino acids from dietary proteins and endogenous protein turnover can be used as an energy source in animals. Carnivores can obtain about 90% of their energy needs from amino acid oxidation after eating. Amino acids are broken down into common intermediate metabolites through transamination and deamination reactions. Excess amino groups are removed as ammonia, which is converted to less toxic urea primarily in the liver and excreted by the kidneys.
The document discusses the determination of the primary structure of proteins. It begins by explaining that proteins are composed of amino acid residues linked by peptide bonds to form a polypeptide chain. The primary structure refers to the specific sequence of amino acids in this chain. Mass spectrometry and tandem mass spectrometry techniques are used to analyze protein fragments obtained through enzymatic or chemical cleavage to determine the amino acid sequence and thereby elucidate the primary structure.
Structures and Functions of Biological Molecules Grade 11 Biology.pptxCjAndreaBeth
This ppt is actually my Performance Task but Bagyong Oddette came and unfortunately I didn't pass this ppt, hope a lot of youngsters being able to use this
Bioenergetics is the quantitative study of energy conversions that occur in living cells, including sunlight used in photosynthesis, electrical nerve impulses, muscle contractions, and heat from chemical reactions. The major source of biological energy is chemical reactions inside cells. Cellular respiration includes glycolysis, the citric acid cycle, and the electron transport chain, which produce carbon dioxide, water, ATP, and heat. ATP is an important energy carrier that is regenerated through oxidative phosphorylation. Other important energy carriers include NAD+/NADH, FAD/FADH2, and coenzyme A.
AMINO ACID power presentation that describes amino acidsArmiyahuAlonigbeja
Here are the answers to your review questions:
1. The regulatory reaction for the urea cycle is the formation of carbamoyl phosphate, which is catalyzed by carbamoyl phosphate synthetase I in the liver mitochondria.
2. Ornithine, citrulline, arginine, aspartate, argininosuccinate.
3. Three ATP molecules are needed to make one molecule of urea in the urea cycle.
4. The Krebs bicycle links the urea cycle and citric acid cycle. CO2 produced in the citric acid cycle is used for urea synthesis, and fumarate can be converted to oxaloacetate, linking the two cycles.
ABSALON_BioChem_Protein and Amino Acid Metabolism.pptxZeref77
Proteins are complex biological molecules composed of amino acids. The body breaks down ingested proteins into individual amino acids, which can then be used to synthesize new proteins or metabolized for energy. Amino acid metabolism involves pathways that classify amino acids as either glucogenic, producing glucose, or ketogenic, producing ketone bodies. Enzymes play an important role in catalyzing the synthesis and breakdown of amino acids, and disorders can occur if these enzymatic pathways are disrupted.
Proteins are essential macromolecules that make up the structure and carry out functions in the body. They are composed of amino acids, which can be synthesized by the body or obtained through diet. Amino acids undergo catabolism through four main stages: transamination, oxidative deamination, ammonia transport, and the urea cycle. The urea cycle is crucial for detoxifying ammonia produced from amino acid catabolism and involves six enzymes that convert ammonia to urea in the liver for excretion. Defects in the urea cycle can cause hyperammonemia, which can be toxic to the brain if not addressed.
This document provides an overview of proteins, amino acids, and peptides. It discusses how proteins perform important biological functions like catalysis, transport, and structure. It describes how amino acids are the building blocks of proteins and the different classifications of amino acids. It also summarizes how peptides are formed from amino acids and some of their functions. The document explains techniques used to separate, purify, and analyze proteins like chromatography, electrophoresis, and spectroscopy.
This document provides an overview of proteins, amino acids, and peptides. It discusses how proteins perform important biological functions like catalysis, transport, and structure. It describes how amino acids are the building blocks of proteins and the different classifications of amino acids. It also summarizes how peptides are formed from amino acids and some of their functions. Finally, it covers common techniques used to separate, analyze, and study proteins like chromatography, electrophoresis, and spectroscopy.
1. Fatty acids from dietary triglycerides and adipose tissue are broken down through beta-oxidation in the mitochondria to produce acetyl-CoA, which feeds into the Krebs cycle.
2. Triglycerides must be emulsified to be digested and transported via chylomicrons in the bloodstream for use or storage.
3. Amino acids are broken down through transamination and the urea cycle to remove nitrogenous waste, while their carbon skeletons can be used for energy or biosynthesis as either glucogenic or ketogenic intermediates.
Examples in biomolecules - proteins, lipids, carbohydrates, and nucleic acid
Examples in biomolecules - proteins, lipids, carbohydrates, and nucleic acid
Examples in biomolecules - proteins, lipids, carbohydrates, and nucleic acid
Examples in biomolecules - proteins, lipids, carbohydrates, and nucleic acid
Examples in biomolecules - proteins, lipids, carbohydrates, and nucleic acid
Examples in biomolecules - proteins, lipids, carbohydrates, and nucleic acid
Examples in biomolecules - proteins, lipids, carbohydrates, and nucleic acidExamples in biomolecules - proteins, lipids, carbohydrates, and nucleic acidExamples in biomolecules - proteins, lipids, carbohydrates, and nucleic acid Examples in biomolecules - proteins, lipids, carbohydrates, and nucleic acid
Examples in biomolecules - proteins, lipids, carbohydrates, and nucleic acid
Examples in biomolecules - proteins, lipids, carbohydrates, and nucleic acid
Examples in biomolecules - proteins, lipids, carbohydrates, and nucleic acid
Examples in biomolecules - proteins, lipids, carbohydrates, and nucleic acid
Examples in biomolecules - proteins, lipids, carbohydrates, and nucleic acid
Examples in biomolecules - proteins, lipids, carbohydrates, and nucleic acidExamples in biomolecules - proteins, lipids, carbohydrates, and nucleic acidExamples in biomolecules - proteins, lipids, carbohydrates, and nucleic acidExamples in biomolecules - proteins, lipids, carbohydrates, and nucleic acid
Examples in biomolecules - proteins, lipids, carbohydrates, and nucleic acid
Examples in biomolecules - proteins, lipids, carbohydrates, and nucleic acid
Examples in biomolecules - proteins, lipids, carbohydrates, and nucleic acid
Examples in biomolecules - proteins, lipids, carbohydrates, and nucleic acid
Examples in biomolecules - proteins, lipids, carbohydrates, and nucleic acid
Examples in biomolecules - proteins, lipids, carbohydrates, and nucleic acidExamples in biomolecules - proteins, lipids, carbohydrates, and nucleic acidExamples in biomolecules - proteins, lipids, carbohydrates, and nucleic acidExamples in biomolecules - proteins, lipids, carbohydrates, and nucleic acid
Examples in biomolecules - proteins, lipids, carbohydrates, and nucleic acid
Examples in biomolecules - proteins, lipids, carbohydrates, and nucleic acid
Examples in biomolecules - proteins, lipids, carbohydrates, and nucleic acid
Examples in biomolecules - proteins, lipids, carbohydrates, and nucleic acid
Examples in biomolecules - proteins, lipids, carbohydrates, and nucleic acid
Examples in biomolecules - proteins, lipids, carbohydrates, and nucleic acidExamples in biomolecules - proteins, lipids, carbohydrates, and nucleic acidExamples in biomolecules - proteins, lipids, carbohydrates, and nucleic acid Examples in biomolecules - proteins, lipids, carbohydrates, and nucleic acid
Examples in biomolecules - proteins, lipids, carbohydrates, and nucleic acid
Examples in biomolecules - proteins, lipids, carbohydrates, and nucleic acid
Example
Metabolism and Energy: The images have big font size and reduced background color. Useful for smartphones, classroom and printouts. The rest is standard stuff.
The document discusses bioenergetics and several key concepts:
1) Photosynthesis captures energy from sunlight and converts it to chemical energy stored in glucose, which all animals obtain directly or indirectly.
2) Cellular respiration releases energy by combining oxygen and energy-rich compounds to produce ATP, the primary energy carrier in cells.
3) Metabolism consists of catabolic reactions that break down molecules and anabolic reactions that use energy from catabolism to build molecules. Metabolic pathways involve a series of reactions to produce a product.
This document provides an overview of microbial metabolism. It discusses the two types of metabolism - anabolism and catabolism. Anabolism involves building complex molecules from simple ones and requires energy, while catabolism breaks down complex molecules into simple ones and generates energy. Key metabolic pathways like glycolysis, the tricarboxylic acid cycle, and the electron transport chain are described. Aerobic respiration and fermentation are compared in terms of the pathways and molecules involved as well as ATP yield. Control mechanisms of enzyme activity like feedback inhibition and induction are also summarized.
This document discusses protein and amino acid metabolism. It covers:
- Amino acids contain nitrogen and are broken down through distinct chemical transformations from carbohydrates and lipids. Excess amino acids form common metabolic intermediates or fuels.
- Humans turnover 1-2% of body protein daily through degradation and resynthesis. Amino acids are reused, and nitrogen forms urea.
- Intracellular proteins have varying half-lives from minutes to weeks and are continuously synthesized and degraded through two major pathways - lysosomal and ubiquitin pathways.
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
Amino acids, Structure of Protein and Amino acid metabolism Pramod Pandey
This document provides an overview of amino acids and protein structure and metabolism. It begins with definitions of amino acid structure and classifications based on properties. It then discusses protein structure at the primary, secondary, tertiary and quaternary levels. Key metabolic pathways of amino acids are covered, including transamination, deamination, the urea cycle, and the metabolism of specific amino acids like glycine, phenylalanine, tyrosine, and tryptophan.
Chapters 18 - Amino acid Oxidation , production of urea Biochemistry Areej Abu Hanieh
Chapters 18 - Amino acid Oxidation , production of urea Biochemistry
the link for chapter 22 : https://www.slideshare.net/arijabuhaniyeh/chapters-18-22-biochemistry-74720233
The document discusses key concepts in metabolism including photosynthesis, cellular respiration, ATP, and free energy. Photosynthesis uses light energy to convert CO2 and H2O into organic molecules and oxygen. Cellular respiration in mitochondria converts organic molecules back into CO2 and uses the energy released to produce ATP, which powers most cellular work. Metabolic pathways are classified as either catabolic, which breaks down molecules and releases energy, or anabolic, which builds molecules and requires energy. ATP acts as the main energy carrier in cells by coupling exergonic reactions to endergonic reactions like chemical work, transport work, and mechanical work.
Secondary metabolism refers to metabolic pathways that are not essential for growth, development or reproduction in organisms. Secondary metabolites are compounds produced by these pathways that usually have ecological functions. There are a few key building blocks that contribute to secondary metabolite production, including acetate, shikimate acid, mevalonate, and amino acids. Secondary metabolites play important roles in plant defense against predators and attraction of pollinators, and are classified based on their structures and biosynthetic pathways.
This document discusses depreciation accounting concepts, objectives, causes, and methods. It defines depreciation as the allocation of an asset's cost over its useful life. Objectives of depreciation include matching revenues and expenses to determine profit, and recovering an asset's cost over the periods it benefits the company. Causes of depreciation include wear and tear, aging, and obsolescence. Common depreciation methods include straight-line, written down value, and sum of years digits. The document also covers depreciation calculations, accounting entries, and policies for different asset types.
The document discusses the structure and functions of cell membranes. It introduces the fluid-mosaic model and defines key terms related to pH, acids, bases, and buffers. pH measures the hydrogen ion concentration in solutions and indicates whether they are acidic or alkaline. Buffers resist changes in pH and their effectiveness depends on the environment's pH. The passage also notes that blood pH is normally between 7.35-7.45, and that conditions outside this range, like acidosis or alkalosis, require compensatory mechanisms.
Bioenergetics is the quantitative study of energy conversions that occur in living cells, including sunlight used in photosynthesis, electrical nerve impulses, muscle contractions, and heat from chemical reactions. The major source of biological energy is chemical reactions inside cells. Cellular respiration includes glycolysis, the citric acid cycle, and the electron transport chain, which produce carbon dioxide, water, ATP, and heat. ATP is an important energy carrier that is regenerated through oxidative phosphorylation. Other important energy carriers include NAD+/NADH, FAD/FADH2, and coenzyme A.
AMINO ACID power presentation that describes amino acidsArmiyahuAlonigbeja
Here are the answers to your review questions:
1. The regulatory reaction for the urea cycle is the formation of carbamoyl phosphate, which is catalyzed by carbamoyl phosphate synthetase I in the liver mitochondria.
2. Ornithine, citrulline, arginine, aspartate, argininosuccinate.
3. Three ATP molecules are needed to make one molecule of urea in the urea cycle.
4. The Krebs bicycle links the urea cycle and citric acid cycle. CO2 produced in the citric acid cycle is used for urea synthesis, and fumarate can be converted to oxaloacetate, linking the two cycles.
ABSALON_BioChem_Protein and Amino Acid Metabolism.pptxZeref77
Proteins are complex biological molecules composed of amino acids. The body breaks down ingested proteins into individual amino acids, which can then be used to synthesize new proteins or metabolized for energy. Amino acid metabolism involves pathways that classify amino acids as either glucogenic, producing glucose, or ketogenic, producing ketone bodies. Enzymes play an important role in catalyzing the synthesis and breakdown of amino acids, and disorders can occur if these enzymatic pathways are disrupted.
Proteins are essential macromolecules that make up the structure and carry out functions in the body. They are composed of amino acids, which can be synthesized by the body or obtained through diet. Amino acids undergo catabolism through four main stages: transamination, oxidative deamination, ammonia transport, and the urea cycle. The urea cycle is crucial for detoxifying ammonia produced from amino acid catabolism and involves six enzymes that convert ammonia to urea in the liver for excretion. Defects in the urea cycle can cause hyperammonemia, which can be toxic to the brain if not addressed.
This document provides an overview of proteins, amino acids, and peptides. It discusses how proteins perform important biological functions like catalysis, transport, and structure. It describes how amino acids are the building blocks of proteins and the different classifications of amino acids. It also summarizes how peptides are formed from amino acids and some of their functions. The document explains techniques used to separate, purify, and analyze proteins like chromatography, electrophoresis, and spectroscopy.
This document provides an overview of proteins, amino acids, and peptides. It discusses how proteins perform important biological functions like catalysis, transport, and structure. It describes how amino acids are the building blocks of proteins and the different classifications of amino acids. It also summarizes how peptides are formed from amino acids and some of their functions. Finally, it covers common techniques used to separate, analyze, and study proteins like chromatography, electrophoresis, and spectroscopy.
1. Fatty acids from dietary triglycerides and adipose tissue are broken down through beta-oxidation in the mitochondria to produce acetyl-CoA, which feeds into the Krebs cycle.
2. Triglycerides must be emulsified to be digested and transported via chylomicrons in the bloodstream for use or storage.
3. Amino acids are broken down through transamination and the urea cycle to remove nitrogenous waste, while their carbon skeletons can be used for energy or biosynthesis as either glucogenic or ketogenic intermediates.
Examples in biomolecules - proteins, lipids, carbohydrates, and nucleic acid
Examples in biomolecules - proteins, lipids, carbohydrates, and nucleic acid
Examples in biomolecules - proteins, lipids, carbohydrates, and nucleic acid
Examples in biomolecules - proteins, lipids, carbohydrates, and nucleic acid
Examples in biomolecules - proteins, lipids, carbohydrates, and nucleic acid
Examples in biomolecules - proteins, lipids, carbohydrates, and nucleic acid
Examples in biomolecules - proteins, lipids, carbohydrates, and nucleic acidExamples in biomolecules - proteins, lipids, carbohydrates, and nucleic acidExamples in biomolecules - proteins, lipids, carbohydrates, and nucleic acid Examples in biomolecules - proteins, lipids, carbohydrates, and nucleic acid
Examples in biomolecules - proteins, lipids, carbohydrates, and nucleic acid
Examples in biomolecules - proteins, lipids, carbohydrates, and nucleic acid
Examples in biomolecules - proteins, lipids, carbohydrates, and nucleic acid
Examples in biomolecules - proteins, lipids, carbohydrates, and nucleic acid
Examples in biomolecules - proteins, lipids, carbohydrates, and nucleic acid
Examples in biomolecules - proteins, lipids, carbohydrates, and nucleic acidExamples in biomolecules - proteins, lipids, carbohydrates, and nucleic acidExamples in biomolecules - proteins, lipids, carbohydrates, and nucleic acidExamples in biomolecules - proteins, lipids, carbohydrates, and nucleic acid
Examples in biomolecules - proteins, lipids, carbohydrates, and nucleic acid
Examples in biomolecules - proteins, lipids, carbohydrates, and nucleic acid
Examples in biomolecules - proteins, lipids, carbohydrates, and nucleic acid
Examples in biomolecules - proteins, lipids, carbohydrates, and nucleic acid
Examples in biomolecules - proteins, lipids, carbohydrates, and nucleic acid
Examples in biomolecules - proteins, lipids, carbohydrates, and nucleic acidExamples in biomolecules - proteins, lipids, carbohydrates, and nucleic acidExamples in biomolecules - proteins, lipids, carbohydrates, and nucleic acidExamples in biomolecules - proteins, lipids, carbohydrates, and nucleic acid
Examples in biomolecules - proteins, lipids, carbohydrates, and nucleic acid
Examples in biomolecules - proteins, lipids, carbohydrates, and nucleic acid
Examples in biomolecules - proteins, lipids, carbohydrates, and nucleic acid
Examples in biomolecules - proteins, lipids, carbohydrates, and nucleic acid
Examples in biomolecules - proteins, lipids, carbohydrates, and nucleic acid
Examples in biomolecules - proteins, lipids, carbohydrates, and nucleic acidExamples in biomolecules - proteins, lipids, carbohydrates, and nucleic acidExamples in biomolecules - proteins, lipids, carbohydrates, and nucleic acid Examples in biomolecules - proteins, lipids, carbohydrates, and nucleic acid
Examples in biomolecules - proteins, lipids, carbohydrates, and nucleic acid
Examples in biomolecules - proteins, lipids, carbohydrates, and nucleic acid
Example
Metabolism and Energy: The images have big font size and reduced background color. Useful for smartphones, classroom and printouts. The rest is standard stuff.
The document discusses bioenergetics and several key concepts:
1) Photosynthesis captures energy from sunlight and converts it to chemical energy stored in glucose, which all animals obtain directly or indirectly.
2) Cellular respiration releases energy by combining oxygen and energy-rich compounds to produce ATP, the primary energy carrier in cells.
3) Metabolism consists of catabolic reactions that break down molecules and anabolic reactions that use energy from catabolism to build molecules. Metabolic pathways involve a series of reactions to produce a product.
This document provides an overview of microbial metabolism. It discusses the two types of metabolism - anabolism and catabolism. Anabolism involves building complex molecules from simple ones and requires energy, while catabolism breaks down complex molecules into simple ones and generates energy. Key metabolic pathways like glycolysis, the tricarboxylic acid cycle, and the electron transport chain are described. Aerobic respiration and fermentation are compared in terms of the pathways and molecules involved as well as ATP yield. Control mechanisms of enzyme activity like feedback inhibition and induction are also summarized.
This document discusses protein and amino acid metabolism. It covers:
- Amino acids contain nitrogen and are broken down through distinct chemical transformations from carbohydrates and lipids. Excess amino acids form common metabolic intermediates or fuels.
- Humans turnover 1-2% of body protein daily through degradation and resynthesis. Amino acids are reused, and nitrogen forms urea.
- Intracellular proteins have varying half-lives from minutes to weeks and are continuously synthesized and degraded through two major pathways - lysosomal and ubiquitin pathways.
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
Amino acids, Structure of Protein and Amino acid metabolism Pramod Pandey
This document provides an overview of amino acids and protein structure and metabolism. It begins with definitions of amino acid structure and classifications based on properties. It then discusses protein structure at the primary, secondary, tertiary and quaternary levels. Key metabolic pathways of amino acids are covered, including transamination, deamination, the urea cycle, and the metabolism of specific amino acids like glycine, phenylalanine, tyrosine, and tryptophan.
Chapters 18 - Amino acid Oxidation , production of urea Biochemistry Areej Abu Hanieh
Chapters 18 - Amino acid Oxidation , production of urea Biochemistry
the link for chapter 22 : https://www.slideshare.net/arijabuhaniyeh/chapters-18-22-biochemistry-74720233
The document discusses key concepts in metabolism including photosynthesis, cellular respiration, ATP, and free energy. Photosynthesis uses light energy to convert CO2 and H2O into organic molecules and oxygen. Cellular respiration in mitochondria converts organic molecules back into CO2 and uses the energy released to produce ATP, which powers most cellular work. Metabolic pathways are classified as either catabolic, which breaks down molecules and releases energy, or anabolic, which builds molecules and requires energy. ATP acts as the main energy carrier in cells by coupling exergonic reactions to endergonic reactions like chemical work, transport work, and mechanical work.
Secondary metabolism refers to metabolic pathways that are not essential for growth, development or reproduction in organisms. Secondary metabolites are compounds produced by these pathways that usually have ecological functions. There are a few key building blocks that contribute to secondary metabolite production, including acetate, shikimate acid, mevalonate, and amino acids. Secondary metabolites play important roles in plant defense against predators and attraction of pollinators, and are classified based on their structures and biosynthetic pathways.
This document discusses depreciation accounting concepts, objectives, causes, and methods. It defines depreciation as the allocation of an asset's cost over its useful life. Objectives of depreciation include matching revenues and expenses to determine profit, and recovering an asset's cost over the periods it benefits the company. Causes of depreciation include wear and tear, aging, and obsolescence. Common depreciation methods include straight-line, written down value, and sum of years digits. The document also covers depreciation calculations, accounting entries, and policies for different asset types.
The document discusses the structure and functions of cell membranes. It introduces the fluid-mosaic model and defines key terms related to pH, acids, bases, and buffers. pH measures the hydrogen ion concentration in solutions and indicates whether they are acidic or alkaline. Buffers resist changes in pH and their effectiveness depends on the environment's pH. The passage also notes that blood pH is normally between 7.35-7.45, and that conditions outside this range, like acidosis or alkalosis, require compensatory mechanisms.
This document summarizes key concepts about carbohydrates. It defines monosaccharides, disaccharides, oligosaccharides, and polysaccharides. It describes the basic composition of carbohydrates including aldoses, ketoses, D and L designations. It explains sugar nomenclature and glycosidic bonds. Examples of specific carbohydrates are given including maltose, cellobiose, sucrose, lactose, amylose, amylopectin, glycogen, cellulose, hyaluronate, heparin, and heparan sulfate. Glycolysis and the citric acid cycle are also summarized.
Vitamins and minerals are essential nutrients that assist many chemical reactions in the body. Vitamins are classified as either fat-soluble (A, D, E, K) or water-soluble (B, C). They help with vision, tissue growth, bone development, and carbohydrate metabolism. Minerals like calcium, phosphorus, and iron are important components of bones and teeth, while others like sodium and potassium help regulate fluid balance and muscle function. Deficiencies can cause conditions like rickets, anemia, or goiter. The body absorbs and stores vitamins and minerals differently, with fat-soluble vitamins accumulating more easily.
Lipids are diverse molecules that include fatty acids, triglycerides, phospholipids, and steroids. They are insoluble in water due to their nonpolar characteristics. Lipids serve important structural and energy storage functions in cells. The main types of lipids are fatty acids, triglycerides, sterols like cholesterol, and phospholipids. Fatty acids can be saturated, monounsaturated, or polyunsaturated depending on the number of double bonds in their hydrocarbon chains. Triglycerides are composed of fatty acids esterified to a glycerol backbone and serve as long-term energy stores. Cholesterol is an important steroid lipid involved in membrane structure and synthesis of hormones and vitamins. Atheros
IPQC tests are important quality control checks performed during the manufacturing of tablets, capsules, and ointments. For tablets, key tests include weight variation, disintegration, dissolution, drug content, hardness, and friability. Tests for capsules include uniformity of content, disintegration, weight variation, and dissolution. Common tests for ointments are not described. IPQC aims to detect errors, minimize human error, and ensure quality at each stage of production according to established procedures.
This document discusses various types of abortion, including spontaneous, threatened, inevitable, complete, incomplete, missed, septic, and habitual abortion. It defines abortion as the expulsion of the fetus weighing less than 1000g before 28 weeks gestation. Spontaneous abortion is the involuntary loss of pregnancy before 28 weeks. Causes can be maternal, fetal, or immunological factors. Treatment depends on the type but may include bed rest, medication, or surgical evacuation of the uterus. The document also covers medical termination of pregnancy (legal abortion) and various methods used in the first and second trimesters.
Mr. X, an 80-year-old male, presented with altered mental status, irrelevant speech, decreased urine output, dry skin, nausea, and vomiting for the past two days. This suggests fluid volume deficit (hypovolemia) likely due to fluid losses from vomiting and diarrhea. Physical assessment should include vital signs, skin turgor, capillary refill time, orthostatic blood pressure, and urine specific gravity. Laboratory tests may show increased BUN and hematocrit. Intravenous isotonic fluids should be given to expand plasma volume along with electrolyte replacement as needed. Nursing care involves monitoring intake and output, daily weights, and signs of circulatory compromise.
The third stage of labor begins after birth and ends with delivery of the placenta, usually within 20 minutes. Complications include postpartum hemorrhage from uterine atony, retained placenta, shock, pulmonary embolism, and rare cases of uterine inversion. Active management with oxytocin administration within 1 minute of birth reduces risks by helping the uterus contract and speeding delivery of the placenta.
This document discusses quality control procedures for raw materials, in-process controls, and finished drug products. It outlines various tests and checks done at different stages of production to ensure product quality and purity. These include sampling and testing of incoming raw materials, in-process checks of attributes like tablet weight and size, and final testing of finished products prior to release. The goals of quality control/assurance programs are to ensure consistent active ingredient amounts within limits, use of ingredients meeting specifications, minimized variability between doses, and high purity and stability of finished products.
This document discusses preoperative nursing care for surgical patients. It covers assessing patients' medical history and surgical risk factors, obtaining informed consent, providing preoperative education on postoperative expectations like pain management and breathing exercises, and establishing nursing diagnoses like anxiety, fear, and knowledge deficits. The goals are to optimize patients' health for surgery and reduce postoperative complications through assessment, teaching, and supportive nursing measures.
A mobile coronary care unit (MCCU) is an ambulance equipped to provide intensive cardiac care and transport critically ill cardiac patients to the hospital. The MCCU has cardiac monitoring equipment, life-saving medications, and a team of paramedics, nurses with cardiac training. Patients receive the same level of care onboard as in a hospital coronary care unit. The MCCU evaluates patients, provides emergency treatment, and transports patients directly to the hospital coronary care unit for further treatment and testing.
quality control test for containers, closures and secondary packing materials...SureshPharamasivam
This document discusses various aspects of pharmaceutical packaging. It begins by defining primary, secondary, and tertiary packaging. The objectives of packaging include marketing, identification, protection, and convenience. Selection of packaging depends on factors like content stability and compatibility. Common packaging materials include glass, plastic, rubber, metals, and paper. The document then discusses various packaging types like containers, closures, collapsible tubes, and unit dose packaging. It outlines tests for evaluating different packaging materials and provides an overview of FDA regulations for pharmaceutical packaging.
HPLC, or high performance liquid chromatography, is an analytical technique used to separate compounds in a mixture. It works by injecting a sample onto a column containing a stationary phase, which causes the different compounds in the mixture to pass through the column at different rates based on their interactions with the stationary and mobile phases. This separation allows for the individual quantification and identification of compounds in the sample. Key aspects of HPLC include the use of high pressure to allow for small particle sizes in the stationary phase, which enables better separation. Common applications of HPLC include the simultaneous analysis of multiple compounds, analysis of compounds at low concentrations, and fractionation of samples for further analysis or purification.
Spontaneous abortion, also known as miscarriage, is the clinically recognized loss of a pregnancy before 20 weeks gestation. It is the most common complication of early pregnancy, with a frequency that decreases with increasing gestational age. Risk factors include advanced maternal age, previous spontaneous abortion, smoking, certain medications, extremes of maternal weight, and maternal infections. Spontaneous abortions are usually due to fetal abnormalities but can also result from maternal factors. Presenting symptoms include vaginal bleeding and pelvic pain. Diagnosis involves pelvic examination, ultrasound criteria, and serial beta hCG levels. Management depends on the classification of abortion as threatened, incomplete, or missed and may involve expectant monitoring, medical treatment, or surgical evacuation
The document describes a smart glove system for deaf and mute people that uses flex sensors and an Arduino board to translate sign language gestures into text or speech. The system captures gestures using flex sensors on a glove connected to an Arduino board. The Arduino board transforms the gestures into text or speech using a text-to-speech converter. An Android app is also proposed to receive the translated messages and output them as voice, allowing deaf people to communicate with others. The system aims to provide an easy and portable way for speech and hearing impaired individuals to communicate.
The document discusses various aspects of accounting for small businesses, including:
- Types of business ownership like sole proprietorships, partnerships, corporations, and LLCs.
- Accounting systems like single entry and double entry accounting. Single entry records transactions only once while double entry uses debits and credits.
- Accounting methods like cash basis and accrual basis for recording revenues and expenses.
- Features of single entry accounting including its simplicity but incompleteness compared to double entry accounting. Methods for determining profit under single entry using net worth or conversion methods are also outlined.
The Joint Commission (TJC) defines a sentinel event as an unexpected occurrence involving death or serious physical or psychological injury. When a sentinel event occurs, hospitals must conduct a root cause analysis within 45 days to determine what factors contributed to the event. Various government agencies have defined lists of specific reportable sentinel events that healthcare facilities must report. Some examples include surgery on the wrong patient, foreign objects left in the body after surgery, and severe neonatal jaundice. Identifying and analyzing these sentinel events helps improve patient safety and quality of care.
It helps in achieving group goals.
2.
Continuous Process: It is a continuous process as activities keep changing.
3.
Horizontal & Vertical: It exists both horizontally & vertically in an organization.
4.
Interdependence: Activities are interdependent & require synchronization.
5.
Achieves Unity of Action: It ensures unity of action & effort.
Importance of Coordination:
1.
Achieves Organizational Goals
2.
Prevents Duplication of Work
3.
Ensures Unity of Command
4.
Facilitates Specialization
5.
Redu
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4. Peptide Bonds Link Amino Acids
• Form when the acid group (COOH) of one amino
acid joins with the amine group (NH2) of a second
amino acid
• Formed through condensation
• Broken through hydrolysis
8. Essential, Nonessential, and
Conditional
• Essential – must be consumed in the diet
• Nonessential – can be synthesized in the body
• Conditionally/Semi essential – cannot be
synthesized due to illness or lack of necessary
precursors
– Premature infants lack sufficient enzymes needed to
create arginine
9. What Are Proteins?
• Large molecules
• Made up of chains of amino acids
• Are found in every cell in the body
• Are involved in most of the body’s functions and
life processes
• The sequence of amino acids is determined by
DNA
10. Structure of Proteins
• Made up of chains of amino acids; classified by
number of amino acids in a chain
– Peptides: fewer than 50 amino acids
• Dipeptides: 2 amino acids
• Tripeptides: 3 amino acids
• Polypeptides: more than 10 amino acids
– Proteins: more than 50 amino acids
• Typically 100 to 10,000 amino acids linked together
• Chains are synthesizes based on specific bodily DNA
• Amino acids are composed of carbon, hydrogen,
oxygen, and nitrogen
11. How Does the Body Use Protein?
• Uses of protein
– Provide structural and mechanical support
– Maintain body tissues
– Functions as enzymes and hormones
– Help maintain acid base balance
– Transport nutrients
– Assist the immune system
– Serve as a source of energy when necessary
12.
13. Paper Chromatography
A method of partition chromatography using filter
paper strips as carrier or inert support.
The factor governing separation of mixtures of solutes
on filter paper is the partition between two
immiscible phases.
One is usually water adsorbed on cellulose fibres in the
paper (stationary phase).
The second is the organic solvent flows past the sample
on the paper (stationary phase).
14.
15. Partition occurs between the mobile phase and the
stationary aqueous phase bound by the cellulose.
Paper chromatography is used to separate amino
acids.
16. 16
Electrophoresis:
The transport of particles through a solvent by an electric field is called
electrophoresis.
In the biological system, many molecules are electrically charged and
will move if electric field is applied.
In electrophoresis, macromolecules are
characterized by their rate of movement in an
electric field.
This technique is used to (1) distinguish molecules
on the basis of charge and shape (2) to determine
molecular weight of proteins (3) to detect amino acid
changes from charged to uncharged residues & (4) to
separate different molecular species quantitatively.
17. 17
Types of Electrophoresis
Moving Boundary Zone
Paper
Gel
Polyacryalmide Agarose
Non Dissociating
(Native-PAGE)
Dissociating
(SDS-PAGE)
18. 18
Gel electrophoresis
* It is used for the separation of proteins and nucleic acids
* Many types of gels are used as supporting medium e.g. starch,
polyacrylamide and agarose
* Earliest work in gel electrophoresis was done with starch
* It provided the first evidence for the existence of isozymes.
* Generally polyacrylamide gels are used for proteins and agarose for
nucleic acids
19.
20. NITROGEN FIXATION
Nitrogen is found in many different organic
and inorganic forms in the atmosphere and
biosphere.
nitrate NO3
-
nitrite NO2
-
hyponitrite N2O2
2-
nitrogen N2 (80%of air)
ammonia NH3
amino acids
protein
purines
pyrimidines
biogenic amines
Inorganic organic
Inorganic nitrogen can be used by plants and bacteria.
Nitrogen used by animals exists in organic forms.
21. The nitrogen cycle
• Soil bacteria play a significant role in cycling
nitrogen through the biosphere:
• Nitrogenase containing bacteria N2 NH3
• Nitrite bacteria (Nitrosomonas) NH3 NO2
-
• Nitrate bacteria (Nitrobacter) NO2
- NO3
-
• Denitrifying bacteria NO3
- N2
22. N N + 3 H2 2 NH3
A bond very
difficult to break.
• This is a reduction reaction of N2, and is
thermodynamically unfavorable.
• 16 ATP is required to fix one molecule of N2.
Biological Nitrogen Fixation
• N2 is converted by some bacteria into ammonia
(NH3) that can be used by plants.
23. Biological significance of nitrogen fixation
- a self fertilization system for plants.
Some bacteria can develop specific association with
certain plants.
Legume plants, after being infected by bacteria
(Clostridia) will form tumor-like nodules on their roots,
which allows cooperative association between bacteria
and plants.
The plants produce carbohydrate for bacteria; and bacteria
provide ammonia to plants by carrying out N fixation.
24. Biosynthesis of amino acids
• While each amino acids has a unique
biosynthetic pathway, each shares several
common features:
– There are six biosynthetic families based on
common precursors.
– Amino acids obtain their carbon skeletons from
an intermediate of glycolysis, citric acid cycle or
phosphogluconate pathway.
– -NH2 usually comes from glutamate.
25. Essential amino acids
• Produced by plants and bacteria.
• Biosynthesis involves longer and more complex
pathways.
• Example
• Synthesis of phenylalanine, tyrosine and
tryptophan.
• They share two to three common steps.
26. Essential amino acids
COO-
OH
O C
COO-
O
P C
H2
C
OH
H
C
OH
H
C
O
H
H2C C
P
COO-
+
erythrose
4-phosphate
phosphoenol-
pyruvate
several
steps
2 Pi
Chorismate
to tryptophan to tyrosine &
phenylalanine
27. COO-
OH
O C
COO-
O
Chorismate
COO-
H2N
N
H
C C H
H
H
NH3
+
COO-
Anthranilate
Tryptophan
CH2
C
COO-
O
CH2
C
COO-
H
+
H3N
CH2
C
COO-
O
OH
CH2
C
COO-
H
+
H3N
OH
Phenylpyruvate Phenylalanine
p-Hydroxyphenyl
pyruvate
Tyrosine
28. Six biosynthetic families based on
common precursors.
Pyruvate
Alanine
Valine
Leucine
Oxaloacetate
Aspartate
Asparagine
Methionine
Lysine
Threonine
Isoleucine
Ribose-5-phosphate
Histidine
-Ketoglutarate
Glutamate
Glutamine
Proline
Arginine
3-Phosphoglycerate
Serine
Cysteine
Glycine
Phosphoenolpyruvate
Tryptophan
Phenylalanine
Tyrosine
29. pyruvate + glutamate alanine + -ketoglutarate
oxaloacetate +glutamate aspartate +-ketoglutarate
alanine
aminotransferase
aspartate
aminotransferase
Alanine can be synthesized from the interaction between
pyruvate and glutamate. Pyruvate gains an amino group
to become alanine, and glutamate loses –NH2 and
oxidized to become a-ketoglutarate.
30. Glutamate synthesis
COO-
C O
CH2
CH2
COO-
+ NH4
+
+ NADPH + H
+
COO-
C H
CH2
CH2
COO-
H3N+
+H2O +NADP
+
glutamate
dehydrogenase
-ketoglutarate glutamate
The process of amino group addition is called
amination.
-ketoglutarate ties this process to the citric acid cycle.
31. Glutamine synthesis
+ NH4
+
+ ATP
COO-
C H
CH2
CH2
C
H3N+
+ ADP + Pi
glutamine
synthetase
COO-
C H
CH2
CH2
COO-
H3N+
O
NH2
Glutamate can be further aminated to form glutamine.
32. Glutamate and glutamine
• All life has the glutamate dehydrogenase
and glutamine synthetase.
• In addition, higher plants and prokaryotes
have glutamate synthase.
-ketoglutarate + glutamine + NADPH + H+
• 2 glutamate + NADP+
glutamate synthase
33. Nonessential amino acids
• Those that can be produced by animals.
• Pathways are relatively straightforward.
• pyruvate + glutamate alanine + -ketoglutarate
• oxaloacetate + glutamate aspartate +-ketoglutarate
• Some pathways are more complex, like the one
for serine.
alanine
aminotransferase
aspartate
aminotransferase
34. Biosynthesis of serine
COO-
C
H OH
CH2
OPO3
2-
COO-
C O
CH2
OPO3
2-
COO-
C H
CH2
OPO3
2-
H3
+
N
COO-
C H
CH2
OH
H3
+
N
hydrolysis
NAD+ NADH + H+
glutamate
-ketoglutarate
H2O
Pi
oxidation-reduction
transamination
3-phosphoglycerate
3-phospho-
hydroxy-
pyruvate
3-phospho-
serine
serine
35. Biosynthesis of glycine
• Glycine is synthesized from serine.
• It uses an unusual process - a one carbon
transfer.
• Tetrahydrofolate (FH4) is an essential cofactor
for this reaction.
36. Biosynthesis of glycine
COO-
C
CH2OH
H3
+
N H
C
C
N
H
CH2
H
N
CH2
H
N
H
COO-
C
H
H3
+
N H
N
CH2
H
N
CH2
H
N
C
H2
+
+
Serine
Glycine
Tetrahydrofolate
N5,N10-Methylene-
tetrahydrofolate
37. Major metabolic pathways
of amino acids
Dietary
protein
Body
protein
Amino acid
pool
Liver
synthesis
Nitrogen
Compounds
citric acid
cycle
urea
cycle
turnover
catabolism
digestion
carbon
skeleton
NH4
+
38. Amino acid Catabolism
• Amino acids cannot be stored.
• If there is an excess of amino acids or a lack
of other energy sources, the body will use
them for energy production.
Amino acid degradation requires the
removal of the amino group as ammonium.
• Ammonium must then be disposed of as it is
toxic to the body.
39. • Amino acids are only used as fuel when:
• Too much protein is ingested
• Normal recycling of protein
• Starvation/diabetes.
• Catabolic pathways
• Each amino acid has a unique pathway.
• All are converted to mainstream metabolites.
40. Catabolism of amino acids starts with
deamination.
After losing the amino group the rest of the
carbon skeleton can usually enter TCA cycle as
intermediate molecules for energy production.
41. • Removal of amino group is a two step
process.
–Transamination reaction
• Aminotransferase moves the amino group to
to a -Keto acid to form another amino acid.
The amino group receiver is usually -
ketoglutarate to produce glutamate.
–Oxidative deamination
• Removal of the amino group from glutamate
producing an ammonium ion.
43. The purpose of transamination is to transfer the
amino groups to one species of a.a. (glutamate)
that can be used for further nitrogen metabolism,
either synthesis of other amino acid or elimination
of NH4+.
46. • Ketogenic amino acids (Isoleucine, leucine, isolucine and
tyrosine…)
• Degraded to acetyl CoA or acetoacetyl CoA
• Produce ketone bodies.
• Glucogenic amino acids (argenine, glutamate, valine
aspartate…)
• Degraded to pyruvate, -ketoglutarate, succinyl
CoA, fumarate or oxaloacetate.
• They can then be used for glucose synthesis.
Catabolism of the carbon skeleton
47. • Isoleucine, leucine and valine share some
steps in their catabolism.
• Transamination is catalyzed by branched-chain
aminotransferase.
• After transamination, ketoproducts are then
decarboxylated via a complex similar to the
pyruvate dehydrogenase complex.
• Their catabolism then proceeds in different
directions.
49. • Phenylalanine catabolism
• Transamination does not occur as the first step. It is
initially hydroxylated to tyrosine
CH2
C
H +
NH3
COO-
CH2
C
H +
NH3
COO-
OH
phenylalanine
hydroxylase
phenylalanine tyrosine
p-hydroxyphenypyruvate
CH2
C
O
COO-
OH
Transamination
51. Where amino acids enter cycle
tyrosine
phenylalanine
aspartate
oxaloacetate
citrate
-ketoglutarate
succinyl
CoA
fumarate
pyruvate
acetyl
CoA
acetoacetyl
CoA
glutamate, glutamine
proline, arginine
isoleucine
leucine
tryptophan
leucine
lysine
phenylalanine
tryosine
tryptophan
isoleucine
methionine
valine
asparagine
aspartate
alanine, glycine
serine, threonine
tryptophan
52. Elimination of ammonium ion
• NH4+ is produced from amino acid catabolism is toxic
and must be eliminated.
• NH4+ is eliminated through the urea cycle
that occurs in the liver.
• The urea cycle
–Occurs in the liver.
–Results in the formation of urea.
–Urea is eliminated by excretion (urine).
53. • Urea cycle is a five-step pathway carried out by
liver cells.
• The strategy is to synthesize arginine that is
then hydrolyzed to release urea and L-ornithine
54. COO- NH2 COO-
| | |
-OOC-CH2CH-N=C-NH-(CH2)3CH
L-argininosuccinate
NH4
+ + CO2 carbamoyl
phosphate
O O
| | | |
H2N-C-O-P-O-
|
O-
O NH3
+
| | |
H2N-C-NH-(CH2)3CH-COO-
L-citrulline
NH3
+
|
-OOCCH2CH-COO-
L-aspartate
NH3
+
|
+H3N-(CH2)3CH-COO-
L-ornithine
-OOC-CH=CH-COO-
fumarate
NH2 NH3
+
| |
+H2N=C-NH-(CH2)3CH-COO-
L-arginine
O
| |
H2N-C-NH2
urea
ATP
AMP
+ PPi
H2O
Pi
2 ATP + 2 H2O
2 ADP
+ Pi
Urea
Cycle
55. • A complete block of any step of the urea
cycle is incompatible with life.
• No alternate pathway for NH4
+ elimination.
• Some genetic disorders will affect
arginase
carbamoyl phosphate synthase
ornithine transcarbamoylase
57. Enzymes - Introduction
• A protein with catalytic properties due to its power
of specific activation
• Chemical reactions need an initial input of energy =
THE ACTIVATION ENERGY
• During this part of the reaction the molecules are
said to be in a transition state.
61. Coenzymes
• An additional non-
protein molecule that is
needed by some
enzymes to help the
reaction is cofactor
• Tightly bound cofactors
are called prosthetic
groups
• Cofactors that are bound
and released easily are
called coenzymes
• Many vitamins are
coenzymes (eg) Biotin
Nitrogenase enzyme with Fe, Mo and ADP cofactors
62. The substrate
• The substrate of an enzyme are the reactants
that are activated by the enzyme
• Enzymes are specific to their substrates
• The specificity is determined by the active site
64. 1. Oxidoreductases
• Oxidoreductases :catalyze the transfer of
hydrogen or oxygen atoms or electrons from
one substrate to another, also called
oxidases, dehydrogenases, or reductases.
Note that since these are ‘redox’ reactions,
an electron donor/acceptor is also required
to complete the reaction.
65. 2. Transferases
• 2. Transferases – catalyze group transfer
reactions, excluding oxidoreductases (which
transfer hydrogen or oxygen and are EC 1).
These are of the general form:
• A-X + B ↔ BX + A
66. 3. Hydrolases
• 3. Hydrolases – catalyze hydrolytic reactions.
Includes lipases, esterases, nitrilases,
peptidases/proteases. These are of the
general form:
• A-X + H2O ↔ X-OH + HA
67. 4. Lyases
• 4. Lyases – catalyze non-hydrolytic (covered in
EC 3) removal of functional groups from
substrates, often creating a double bond in the
product; or the reverse reaction, ie, addition of
function groups across a double bond.
• A-B → A=B + X-Y
X Y
• Includes decarboxylases and aldolases in the
removal direction, and synthases in the addition
direction.
68. 5. Isomerases
• 5. Isomerases – catalyzes isomerization
reactions, including racemizations and cis-
tran isomerizations.
69. 6. Ligases
• 6. Ligases -- catalyzes the synthesis of various
(mostly C-X) bonds, coupled with the
breakdown of energy-containing substrates,
usually ATP
70. Mechanism of Action of Enzymes
1. The Lock and Key Hypothesis
• Fit between the substrate and the active site of the enzyme is
exact
• Like a key fits into a lock very precisely
• The key is analogous to the enzyme and the substrate
analogous to the lock.
• Temporary structure called the enzyme-substrate complex
formed
• Products have a different shape from the substrate
• Once formed, they are released from the active site
• Leaving it free to become attached to another substrate
71. The Lock and Key Hypothesis
Enzyme
may be
used again
Enzyme-
substrate
complex
E
S
P
E
E
P
Reaction coordinate
72. The Lock and Key Hypothesis
• This explains enzyme specificity
• This explains the loss of activity when
enzymes denature
73. 2. The Induced Fit Hypothesis
• Some proteins can change their shape
(conformation)
• When a substrate combines with an enzyme, it
induces a change in the enzyme’s conformation
• The active site is then moulded into a precise
conformation
• Making the chemical environment suitable for the
reaction
• The bonds of the substrate are stretched to make the
reaction easier (lowers activation energy)
74. The Induced Fit Hypothesis
• This explains the enzymes that can react with a range
of substrates of similar types
Hexokinase (a) without (b) with glucose
substrate
76. Substrate concentration: Non-enzymic reactions
• The increase in velocity is proportional to the
substrate concentration
Reaction
velocity
Substrate
concentration
77. Substrate concentration: Enzymic reactions
• Faster reaction but it reaches a saturation point when all the
enzyme molecules are occupied.
• If you alter the concentration of the enzyme then Vmax will
change too.
Reaction
velocity
Substrate
concentration
Vmax
78. The effect of pH
Optimum pH
values
Enzyme
activity Trypsin
Pepsin
pH
1 3 5 7 9 11
79. The effect of pH
• Extreme pH levels will produce denaturation
• The structure of the enzyme is changed
• The active site is distorted and the substrate
molecules will no longer fit in it
• At pH values slightly different from the enzyme’s
optimum value, small changes in the charges of the
enzyme and it’s substrate molecules will occur
• Optimum pH: The pH at which the given enzyme
exhibits maximum activity is called as Optimum pH.
80. The effect of temperature
• The temperature coefficient = the increase in
reaction rate with a 10°C rise in temperature.
• Enzyme-controlled reactions follow this rule as they
are chemical reactions
• BUT at high temperatures proteins denature
• The optimum temperature for an enzyme controlled
reaction will be a balance between the starting and
denaturation.
81. The effect of temperature
Temperature / °C
Enzyme
activity
0 10 20 30 40 50
Denaturation
82. The effect of temperature
• For most enzymes the optimum temperature is about
30°C
• Many are a lot lower, cold water fish will die at 30°C
because their enzymes denature
• A few bacteria have enzymes that can withstand very
high temperatures up to 100°C. Most enzymes however
are fully denatured at 70°C.
• Optimum temperature: The temperature at which the
given enzyme exhibits maximum activity is called as
Optimum pH.
83. Inhibitors
• Inhibitors are chemicals that reduce the rate
of enzymic reactions.
• The are usually specific and they work at low
concentrations.
• They block the enzyme but they do not usually
destroy it.
• Many drugs and poisons are inhibitors of
enzymes in the nervous system.
84. The effect of enzyme inhibition
• Irreversible inhibitors: Combine with the
functional groups of the amino acids in the
active site, irreversibly.
Examples: Nerve gases and pesticides,
containing organophosphorus, combine with
serine residues in the enzyme acetylcholine
esterase.
85. The effect of enzyme inhibition
• Reversible inhibitors: These can be washed
out of the solution of enzyme by dialysis.
There are two categories.
86. The effect of enzyme inhibition
1. Competitive: These
compete with the
substrate molecules for
the active site.
The inhibitor’s action is
proportional to its
concentration.
Resembles the substrate’s
structure closely.
Enzyme
inhibitor
complex
Reversible
reaction
E + I EI
88. The effect of enzyme inhibition
2. Non-competitive: These are not influenced by the
concentration of the substrate. It inhibits by binding
irreversibly to the enzyme but not at the active
site.
Examples
• Cyanide combines with the Iron in the enzymes
cytochrome oxidase.
• Heavy metals, Ag or Hg, combine with –SH groups.
These can be removed by using a chelating agent such
as EDTA.
89. Applications of inhibitors
• Negative feedback: end point or end product
inhibition
• Poisons snake bite, plant alkaloids and nerve
gases.
• Medicine antibiotics, sulphonamides,
sedatives and stimulants
90.
91. ENZYMES IN MEDICINE
• Diagnostic indicators – the activities of many enzymes are
routinely determined in plasma ( rarely in tissue biopsies) for
diagnostic purposes in diseases of the heart, liver, skeletal muscle,
pancreas and other tissues - enzyme diagnostics
• Therapeutic agents – several enzymes are used as drugs; new
approach - enzymotherapy
• Diagnostic tools – use as chemicals in clinical laboratory assays
92. ENZYMES IN CLINICAL DIAGNOSIS
secretory - produced by tissues (namely liver), acting in plasma –
prothrombin, plasminogen, cerruloplasmin, choline
esterase; lipoprotein lipase
Enzymes
intracellular – function intracellulary, have no physiological use in
plasma
- membrane bound – ALP, GMT
- cytosolic – ALT, AST, LD, MDH
- mitochondrial – AST, GMDH
- lysosomal - ACP
- tissue specific – glucose-6-phosphatase – liver
amylase – pancrease
LD1 – heart
93. Examples of enzymes commonly assayed for diagnostic purposes
Enzyme Location Cause of elevated plasma level
Acid phosphatase - ACP Prostate Prostatic cancer
Alkaline phosphatase – ALP Bone, liver Rickets, hypoparathyroidism,
osteomalacia, obstructive
jaundice, cancer of bone/liver
Alanine aminotransferase – ALT Liver (muscle, Hepatitis, jaundice, circulatory
heart, kidney) faillure with liver congestion
Aspartate aminotransferase – AST Heart, muscle, Myocardial infarction, muscle
red cells, liver damage, anemia, hepatitis,
circulatory faillure with liver
congestion
Amylase - AM Pancres Acute pancreatitis, peptic ulcer
-Glutamyl transferase – GMT Liver, kidney, Hepatitis, alcoholic liver
pancreas damage, cholestasis