- •Federal Agency of Education tambov state university named after g.R. Derzhavin
- •Biochemistry (part I)
- •Tambov 2012
- •I. Theoretical part The subject Of biological chemistry
- •1. Chemistry of proteins
- •1.1. Methods of exctraction and purification of proteins
- •1.2. Functions of proteins
- •1.3. Amino-acid composition of proteins
- •1.4. The structural organization of proteins
- •1.5. Physical and chemical properties of proteins
- •1.6. Classification of proteins
- •1.6.1. Simple proteins
- •1. Albumins and globulins.
- •2. Protamines and histones.
- •3. Prolamins and glutelins.
- •1.6.2. Conjugative proteins
- •1. Proteins containing non-heme iron.
- •Nucleic acids
- •The structure of nucleic acids
- •Test Questions
- •2. Enzymes
- •2.1. The chemical nature of enzymes
- •2.2. The mechanism of enzymes action
- •2.3. Kinetics of enzymatic reactions
- •2.4. Enzyme properties
- •2.5. Regulation of enzyme activity
- •1. Control of the enzyme amount.
- •2. Control of enzyme activity.
- •2.1. The influence of activators and inhibitors on the enzymes.
- •2.3. Chemical modification of the enzyme.
- •2.4. Allosteric regulation.
- •2.6. Classification and nomenclature of enzymes
- •2.7. Enzymes in medicine
- •Test Questions
- •3. Vitamins
- •3.1. Fat soluble vitamins
- •3.2. Water soluble vitamins
- •Vitamin-like substances
- •Test Questions
- •4. Basic principles of biomembranes’ organisation
- •4.1. Structure and functions of membranes
- •1. Phospholipids (90%) - glycerophospholipids and sphingophospholipids:
- •4.2. Transport of substances across membranes
- •2. Facilitated diffusion
- •Test Questions
- •5. Transmembrane transduction of the hormonal signal
- •Test Questions
- •6. Introduction to metabolism
- •6.1. Stages of catabolism
- •III. A common catabolic pathway.
- •6.2. Bioenergetics
- •6.3. Organization and operation of the respiratory chain
- •6.4. Uncoupling of oxidation from phosphorylation
- •6.5. Generation of free radicals in cells
- •6.6. Reactions of the common catabolic pathway
- •6.6.1. Oxidative decarboxylation of pyruvate
- •6.6.2. Citric acid cycle
- •7. Carbohydrate metabolism
- •7.1. Digestion of carbohydrates
- •7.2. Glycogen metabolism
- •7.3. Glycolysis
- •7.4. The inclusion of fructose and galactose
- •In glycolysis
- •7.5. The shuttle mechanisms
- •7.6. Cori cycle
- •7.7. Alcoholic fermentation
- •C6h12o6 → 2 ch3chohcooh
- •7.8. Pentose phosphate pathway (hexose monophosphate shunt)
- •7.9. Gluconeogenesis
- •Synthesis of glucose from the pyruvic acid.
- •Fructose bisphosphatase
- •Glucose-6-phosphatase
- •7.10. Regulation of carbohydrate metabolism
- •Glucose → glucose-6-phosphate.
- •Pyruvate → oxaloacetate → phosphoenolpyruvate
- •7.11. Violations of carbohydrate metabolism
- •Violation of hydrolysis and absorption of carbohydrates
- •Violations of the intermediate metabolism of carbohydrates
- •Quiz Questions
- •II. Laboratory practice Laboratory work 1. The analysis of amino acids and proteins
- •1. Qualitative analysis of amino acid mixtures by thing layer chromatography method.
- •2. Colour reaction of proteins.
- •2.1. Millon’s reaction.
- •2.2. Ninhydrin’s reaction.
- •3. Reactions of precipitation of proteins.
- •3.1. Precipitation of proteins with salts of heavy metals.
- •3.3. Precipitation of proteins with the help of concentrated mineral acids.
- •3.4. Precipitation of proteins by organic acids.
- •Test questions
- •Laboratory work 2. Conjugated proteins: glycoproteins and phosphoproteins
- •1. Phosphoproteins.
- •1.1. Proof of protein component’s present in the casein hydrolyzate.
- •1.2. Proof of phosphoric acid’s presence in the casein hydrolyzate.
- •1.3. Determination of the isoelectric point of casein.
- •2.4. Proof of carbohydrate’s presence in the egg albumin.
- •Test questions
- •Laboratory work 3. Conjugated proteins: nucleoproteins and chromoproteins
- •1. Nucleoproteins
- •1.1. Isolation of deoxyribonucleoproteins from the spleen.
- •1.2. Reaction with diphenylamine.
- •2. Chromoproteins.
- •2.1. Benzidine test for hemin group of hemoglobin.
- •Test questions
- •Laboratory work 4. Enzymes
- •1. Detection of peroxidase in potatoes.
- •2. Detection of pepsin in the gastric juice.
- •3. Hydrolysis of starch by α-amylase.
- •4. Specificity of amylase and sucrase enzymes action.
- •Test questions
- •Laboratory work 5. Identifying the activity of enzymes
- •1. The influence of activators and inhibitors upon activity of enzymes.
- •1. The influence of activators and inhibitors upon α-amylase.
- •1.2. Inhibitory effect of chloride ions on dehydrogenase complex of potatoes.
- •2. Identifying the activity of α-amylase according to Wolgemut.
- •Test questions
- •Inhibitor calimine
- •Laboratory work 6. Vitamins
- •Vitamin a (vitamin a, retinol)
- •Vitamin d (calciferol)
- •3.1. Reaction with concentrated nitric acid.
- •3.2. Reaction with ferric chloride (III).
- •9.2. Reaction with methylene-blue.
- •Test questions
- •Laboratory work 7. Oxidoreductases. Common catabolic pathway
- •1. Comparison of redox-potentials of riboflavin and methylene blue.
- •2. Identifying of catalase activity according to a.N. Bach and а.I. Oparin.
- •Test questions
- •Laboratory work 8. Carbohydrate metabolism
- •2.1. Trommer’s test with copper hydroxide.
- •2.2. Discovery of fructosuria by Selivanov’s test.
- •2.3. Enzymatic method of semi-quantitative identification of glucose in urine with the help of "GlucoPhan" test strip.
- •Test questions
- •References
Test Questions
1. What is the transmembrane transfer of signals?
2. Which compounds can act as primary messengers, second messengers?
3. Describe the main parts and the mechanism of action of adenylatecyclase messenger system.
4. List the major types of regulation of enzyme activity in the cell.
6. Introduction to metabolism
Metabolism (from the Greek "transformation, change") is a set of chemical reactions in living cells, providing growth, development and activity of the body and life in general.
Metabolism consists of two opposing simultaneous processes.
Catabolism includes reactions associated with the breakdown of substances, their oxidation and elimination of waste products from the body. Catabolic reactions are exergonic (give energy).
The organelles of catabolic system are mitochondria, lysosomes, peroxisomes.
(Peroxisomes are cellular organelles, which are carrying out the oxidation of fatty acids, the synthesis of bile acids, cholesterol, etc. Glioxysomes are a kind of peroxisomes, in which the oxidation of glyoxylate cycle and the Krebs cycle going on.)
Anabolism integrates all reactions associated with the synthesis of essential substances, their assimilation and use for growth, development and functioning of the body. Anabolic reactions are usually endergonic (energy consuming). The organelles of anabolic system are endoplasmic reticulum and ribosomes, Golgi apparatus.
Metabolites are products of metabolism of some compounds.
Stages of metabolism:
1. Intake of substances in the body (breathing, eating, digestion).
By digestion polymers (starch, proteins, fats) break down to monomers (amino acids, glucose, etc.), which pass into the blood.
2. Intracellular metabolism (intermediate exchange) is a set of metabolic pathways.
Metabolic pathways are the consistent transformation of one substance into another, of one metabolite into another.
There is usually a reaction in the pathway with a slower rate than others. It is the rate-limiting stage (reaction). It determines the overall rate of conversion of a substance into a final product of the metabolic chain.
The enzyme that catalyzes the rate-limiting reaction is called regulatory one.
The reactions of metabolism are mainly reversible. Their direction is determined by consumption or removing of the product.
Under constant conditions, the concentration of several metabolites in cells and extracellular fluids is constant. In diseases, the steady-state concentrations of metabolites are specifically changed. It is the base of biochemical methods of laboratory diagnostics of diseases.
6.1. Stages of catabolism
Stages of catabolism
I. Hydrolytic stage. Proteins, fats and carbohydrates are broken down into the corresponding monomers under the influence of hydrolases in the digestive tract.
II. Specific pathways of catabolism. Monomers of major nutrients (with the participation of enzymes that are specific to each class of substances) are transformed into two metabolites - pyruvic acid and acetyl-CoA. At this stage, 1/3 energy of nutrients is released.
Acetyl-CoA (acetyl coenzyme A) is the energy-rich product of condensation of coenzyme A with acetic acid. It includes pantothenic acid. Coenzyme A is in the free state in the cell and interacts with the enzyme at the moment of reaction with the substrate.