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Many diseases lead to the accumulation in blood plasma of acids such as lactic, acetoacetic, and β-hydroxybutyric. The accumulation can be so intense that they talk about the occurrence of acidosis, that is, acidification of the blood below normal (pH7.36-7.44). 1) Explain what is danger of acidosis for the body. 2) Name the types of bonds in protein molecules. Write the formation of the formation of ionic and hydrogen bonds. 3) Describe the structures of protein molecules.

1) Acidosis can lead to serious complications, including: osteoporosis, which is a loss of bone that can increase the risk of fractures. improper growth in children, as metabolic acidosis restricts the growth hormone. increased kidney damage, which can worsen chronic kidney disease. Cause - Endocrine diseases. First of all, diabetes mellitus. It is accompanied by instability of insulin levels or insensitivity of tissues to this substance. Can be compensated and uncompensated 2) Peptide bonds, hydrogen bonds, disulfide bonds and ionic bonds The hydrogen bond in the protein molecule is carried out between a hydrogen atom of one grouping having a partially positive charge and an atom (oxygen, nitrogen) having a partially negative charge and an unshielded electron pair of another grouping. In proteins, there are two variants of the formation of hydrogen bonds: between peptide groups.) ionic - as a result of the electrostatic interaction of differently charged functional groups: COO- (dicarboxylic amino acids) and NH3+ (diaminocarboxylic amino acids

Which serum protein moves faster towards the anode during protein electrophoresis? Explain why this is connected. 1) List the properties of this protein, especially its amino acid composition. 2) Write the amino acid formulas that determine its charge? 3) Write a tripeptide at the N-end of which there is a heterocyclic, and at the C-end, a diaminomonocarboxylic essential amino acid, the second amino acid is glutamic.

1) Albumin, because it has the most negative charge 2) Water-soluble, spherical shaped, sensitive to temperature and pH changes. It has 3 domains, which has 2 subdomains linked by disulfide bonds. Used in restoration of oncotic pressure of plasma. ISP is 5, acidic properties. Asp, Glu 3) Phe-Glu-Lys

What enzyme preparation (lysozyme, RNA-ase, hyaluronidase, amylase, fibrinolysin) can be used to accelerate the absorption of certain medicinal substances injected parenterally (for example, during electrophoresis). 1) Select one of the listed enzymes, name the class, subclass. 2) Write the reaction catalyzed by this enzyme using formulas. 3) Describe the role of the substrate for this enzyme.

1) Amylase: Hydrolase class, glycoside hydrolase subclass. 2) stratch - maltose 3) The substrate for amylase is starch, a polysaccharide composed of amylose + amylopectin. The product of the amylase reaction is maltose, a disaccharide (made from two glucose molecules. The only role of starch in the human diet is conversion to glucose for additional energy.

In the biological fluid was created 50% saturation with ammonium sulfate, and the protein was precipitated. After separation of the protein, the liquid became transparent. 1) What color reaction can be used to prove complete precipitation of the protein? What does this reaction reveal? 2) What proteins have precipitated? List the properties of this protein, especially its amino acid composition. 3) Write a tripeptide consisting of two sulfur-containing and one essential hydroxyamino acid.

1) Biuretic reaction a qualitative reaction to all proteins without exception, as well as the products of their incomplete hydrolysis, is due to the presence of peptide bonds in proteins, which form colored copper salt-like complexes with copper (II) sulfate in an alkaline medium. If complete precipitation of proteins has occurred, it should be negative. 2) Globulins/a widespread group of globular proteins, usually accompanying albumins. Globulins have a higher molecular weight than albumins, slightly acidic or neutral proteins, are soluble in weak salt solutions, insoluble in distilled water and precipitate at 50% or more saturation of solutions with ammonium sulfate. Globulins in the body perform nutritional, protective, and transport functions. Globulins are different from albumins - they do not contain glycine at all. It includes a glycoprotein and an antitrypsin 3) Cysteine + methionine + threonine. Cysteylmethionylteronin

When the biological fluid was heated to 100 degrees, precipitate wasn't formed. 1) What reactions can be used to justify the absence or presence of protein in solution? What are the principles on which these reactions are based? 2) What happens to the protein when heated to 100 degrees? Explain the mechanism. 3) Describe the structures of protein molecules

1) Biuretic test: based on the ability of peptide groups of proteins and polypeptides to form a complex colored purple with Cu 2+ ions in an alkaline medium. The ninhydrin test is based on the interaction of ninhydrin with the α-amino group of amino acids, peptides and proteins, resulting in a complex colored blue or violet-blue. Deposition of protein by organic acids - The method is based on the ability of organic matter to cause dehydration of protein and destroy its spatial structure (i.e. cause denaturation). 2) protein denaturation is a change in a protein molecule under the influence of certain factors. The change in the protein molecule consists in the loss of its quaternary and tertiary structures, sometimes secondary and very rarely primary. The loss of the protein of its tertiary structure leads to the loss of its properties, and it can no longer perform its functions. 3) The primary structure is a linear sequence of amino acid residues in a polypeptide chain linked by peptide bonds. Determines the properties- configuration. The secondary structure is the conformation of a polypeptide chain caused by the rotation of its individual sections around single covalent bonds. It is enhanced by hydrogen bonds arising between CO- and NH-groups that are part of various peptide groups. At the level of the secondary structure there are proteins: fibroin, keratin (hair, nails), collagen (tendons). Tertiary structure - The tertiary structure of a protein is the laying of a polypeptide chain in a certain volume due to the establishment of hydrophilic-hydrophobic interactions between. takes the form of globules or fibrils. Quaternary structure is a method of laying several polypeptide chains (subunits) in space, having the same or different primary, secondary and tertiary structures, and forming a single macromolecule.

Pathogenic bacteria Clostridium perfringens anaerobes, which are causative agents of gas gangrene, in which tissue necrosis occurs, secrete an enzyme that effectively catalyzes the hydrolysis of the peptide bond at the carboxyl group of glycine: -Х- gly-pro-У→-Х- gly-СООН + NH2—pro-У- whereХ and У - any of 20 amino acids. 1) How does this secreted enzyme help bacteria to enter human tissue? 2) Name a tissue structural protein that contains a lot of glycine. Characterize the structure of this protein. 3) Why does this enzyme not harm the bacteria itself?

1) Collagen, a protein of the intercellular space, contains 33% glycine. Bacteria have used this trait in their evolution to maximize efficiency with a single enzyme. Hydrolysis of a major protein in the extracellular matrix "loosens" tissue tissue, allowing bacteria to gain living space. 2) Collagen is composed of three chains, wound together in a tight triple helix. A repeated sequence of three amino acids forms this sturdy structure. Every third amino acid is glycine, a small amino acid that fits perfectly inside the helix. Many of the remaining positions in the chain are filled by two unexpected amino acids: proline and a modified version of proline, hydroxyproline. 11% - are on share alanine, 2 1% - proline and oxyproline. 3) Клеточная стенка бактерий не несет молекул, могущих быть субстратами для этих ферментов, поэтому разрушение бактериальной клетки не происходит

. The molecules of natural proteins contain a large number of residues of a certain amino acid. At the same time, there is a correlation between the content of a given amino acid and the mechanical properties of these proteins (tensile strength, viscosity, hardness). 1) Name the amino acid. Write down the type of bond it forms and determines the mechanical properties of the protein. 2) Name the properties of alpha-keratins, especially the amino acid composition and structure of this protein. 3) Write a tripeptide, taking into account the peculiarities of the amino acid composition of alpha-keratins

1) Cysteine. A disulfide bond is formed when two cysteine residues come together. This bond stabilizes the tertiary structure of the protein molecule. Under the action of reducing agents, this bond is broken with the formation of two sulfhydryl groups (SH). 2) Alpha-keratins are the main type of fibrillar proteins in the composition of skin, hair, wool, feathers, nails, claws, scales, needles, armor, hooves. They contain a lot of cis in their composition. It consists of 3 p / n chains twisted into a superspiral (protofibrill).- microfibrill - macrofibrill. One hair contains hundreds of macrofibrils. Disulfide bridges appear between the n/a chains, which explains the special strength of alpha-keratins. These proteins do not dissolve in water, because the hydrophobic radicals of amino acids contained in large quantities are turned outward. 3) ala+lei+cis

1. A 58-year-old patient complains of pain in the chest area, sudden weakness, sweating, fear, dizziness. The preliminary diagnosis is myocardial infarction. 1) The activity of which three enzymes should be determined in the patient's blood? 2) Which of them have isozyme forms? 3) The activity of which isoenzyme is most informative in the first hours of myocardial infarction?

1) LDH, creatine kinase, AST 2) Lactate dehydrogenase isoenzymes - LDH -1,2,3,4,5 creatine kinase - MM, BB, MB 3) Usually troponins are most widely recognized during MI, within 2-3 hours elevation of troponin occurs after, within 6 -12 hours creatine kinase increases 24 -72 hours LDH increases

Isoelectric point of hemoglobin 6.8. 1) Name (if any) the predominant amino acids in the protein structure. Write the formula for a tripeptide made up of these amino acids. 2) Indicate in which direction hemoglobin will move in an electric field at a pH of 3.4. 3) Name which proteins hemoglobin belongs to, its structure, write the formula for heme and its rational name

1) Leucine, methionine, lysine, tryptophane, and tyrosine fall in a middle group with hemoglobin output of about 20 gm. The composition of hemoglobin includes 2α- and 2β-chains, which are products of the expression of two different genes, and therefore they have a different primary structure. The composition of the α-chain includes 141, and the composition of the β-chain - 146 amino acid residues. 2) Since the IET is greater than the Ph, the hemoglobin will move to the cathode. charge of the protein is positive, the direction of movement is towards the cathode 3) Hemoglobin belongs to the class of chromoproteins, a subclass of hemoproteins The hemoglobin molecule consists of a simple histone-type protein - globin and four hemes. Globin consists of four monomers, two Alpha chains and two Beta chains. Rational name 1,3,5,8 tetramethyl 2,4 divinyl 6,7 dipropionic acid ferro-morphine

Preparations of mercury, arsenic, bismuth are inhibitors of enzymes that have thiol groups (SH-groups) in active centers. 1) What is the inhibition mechanism of these enzymes? 2) What amino acid is used to reactivate these enzymes? 3) What types of bonds can this amino acid form in a protein molecule? Write reactions.

1) Non-competitive. SH-groups bind The apoptic Center irreversibly bind the catalytic site of the enzyme acetylcholinesterase. For example, zinc in the carbonic anhydrase enzyme can be displaced by mercury or lead ions. 2) Cysteine.Enzymes whose inactivation was caused by the oxidation of SH-groups, in some cases it is possible to reactivate with the help of reducing agents, in particular low molecular weight thiols. 3) Cysteine is an amino acid that has an SH-group in the radical, due to which disulfide bonds are formed.

The doctor did not attach importance to the analysis of urine for amylase (an increase in its activity by 10 times). 1) The danger of autolysis of which gland can threaten the patient? 2) What class, subclass does amylase belong to? What is the structure of an enzyme? Write a reaction catalyzed by this enzyme? 3) How to prove the substrate specificity of amylase? What kind of qualitative response

1) Pancreas 2) α-Amylase belongs to the class: Glycosidases . subclass:Glycosidhydrolases E1110 (synonym) it is a major digestive enzyme, and its optimum pH is 6.7-7.0. Transfere glycogen and stratch into maltose. γ-амилаза performs glycogene into glucose and mainly presented in the liver 3) Какого рода качественный ответ? If you chew bread or potatoes (containing starch) for a long time and keep them in your mouth, then after a while a sweet taste is felt, This is a clear example of the breakdown of polysaccharides to disaccharides (maltose)

1. A patient with chronic gastritis has a decrease in the activity of pepsin, the pH of gastric juice is 5.0. 1) Explain the reason for the decrease in pepsin activity. 2) Why were such patients previously prescribed to use a weak solution of hydrochloric acid before meals? 3) What type of specificity is characteristic for this enzyme?

1) Pepsin acts only in the acidic environment of the stomach. The maximum activity of pepsin reaches at pH = 1.9. In chronic gastritis, the pH of gastric juice increases to 5.0, which indicates that pepsin reduces its activity, if the pH reaches 6, then it is inactivated. 2) to create an acidic environment necessary for the action of gastric juice enzymes, denaturation and swelling of proteins in the stomach, which facilitates their subsequent cleavage by pepsins; activates pepsinogens and converts them into pepsins; 3) Pepsin has relative (group) specificity. Once in the stomach, protein substances are broken down by pepsin regardless of the quality and quantity of amino acids included in them due to the fact that amino acids are connected by a peptide bond, which pepsin breaks down. Therefore, the action of pepsin is relatively specific.

. The doctor did not attach importance to the analysis of urine for amylase (an increase in its activity by 10 times). The patient may be in danger of pancreatic autolysis caused by an enzyme (pepsin, amylase, aldolase, trypsin, phosphorylase). 1) Select one of the listed enzymes, name the class, subclass, sub-subclass. 2) The structure of this enzyme and its activator. 3) Write a catalyzed reaction

1) Pepsin belongs to the class of hydrolases, endopeptidases, peptidase subclass-hydrolysis of peptide bonds is carried out. 2) The pepsin molecule is a polypeptide chain, which consists of 340 amino acids, contains 3 disulfide bonds and phosphoric acid. Pepsin is an endopeptidase that cleaves central peptide bonds in protein and peptide molecules to form simpler peptides and free amino acids. Pepsins are endoproteinases with an unusually acidic pH optimum (about pH 2). They cleave the peptide bonds of proteins (between Phe and Leu) with the help of two aspartyl residues in the active center

In a patient with myocardial infarction, increase in the activity of lactate dehydrogenase in the blood serum. 1) To which class, subclass and subclass of enzymes does LDH belong? 2) Write the reaction that the enzyme catalyzes? 3) The chemical nature, structural features of this enzyme, localized in the myocardium.

1) Refers to oxyreductases - dihydrogeneases, a subclass of pyridine enzymes 2) lactic acid - pyruvic 3) LDH is a complex two-component enzyme consisting of an apoenzyme and a coenzyme. The coenzyme can be in the form of NAD and NADP. The active group is the pyridine ring included in the coenzyme. LDH consists of 4 peptide chains of two types - M and H. There are 5 isoforms of LDH, which differ somewhat in chemical and physical properties.

1. In the patient's blood, an increased activity of the MB-form of creatine kinase (CK-MB), LDH and AST was found. Which organ is affected by these changes? 1) What class, subclass are these enzymes? 2) Describe the structure of these enzymes. 3) Write a reaction catalyzed by one of these enzymes.

1) These changes mostly affect the muscular organs: the heart, skeletal muscles, etc. • CK-MB - class of transferases, subclass of phosphotransferases, • Lactate dehydrogenase (LDH)- class of oxidoreductases, subclass of Dehydrogenase, • AST - class transferase subclasse of transaminase 2) ● CK enzymes consist of two subunits, which can be either B (brain type) or M (muscle type). There are, therefore, three different isoenzymes: CK-MM, CK-BB and CK-MB. The genes for these subunits are located on different *chromosomes. ● The active form of lactate dehydrogenase (LHD) is a tetrameter of 4 subunits. Each subunit is formed by a peptide chain of 334 amino acids ● AST is dimeric, consisting of two identical subunits, each with approximately 400 amino acid residues Each subunit is composed of a large and a small domain, as well as a third domain consisting of the N-terminal residues 3-14. secondary structure, AST contains both α and β elements. Each domain has a central sheet of β-strands with α-helices 3)lactat - pyruvat

The protein contains amino acid residues of aspartic acid, leucine, serine, valine, glutamine, lysine, tyrosine. 1) Indicate the most likely location of amino acids (inside or on the surface of the native protein molecule). 2) List the types of bonds involved in the formation of native protein structures. Give examples of the formation of two types of these connections. 3) What is the name of the process by which the structures of protein molecules are disrupted? What factors can cause structural disruption?

1) Valine and leucine will be inside, because it contains a hydrophobic group that should be hidden from water. The rest will be outside, because they are hydrophilic. 2) The tertiary structure of the protein arises from the interaction of amino acid radicals, as well as due to disulfide bridges, hydrogen and ionic bonds. The protein molecule takes the form of a globule. Examples of proteins are keratin, collagen. 1 - ionic bond - occurs between positively and negatively charged functional groups; 2 - hydrogen bond - occurs between an uncharged hydrophilic group and any other hydrophilic group; 3 - hydrophobic interactions - occur between hydrophobic radicals; 4 - disulfide bband- formed due to the oxidation of SH-groups of cysteine residues and their interaction with each other 3) Denaturation. It can be caused by high temperature, alkalis, heavy metal salts

If woolen sweater or wool socks washed in hot water and then dried quickly, that they become smaller. At the same time, silk under the same conditions does not give such shrinkage. 1) Based on the role and structure of alpha keratin, how do you explain this phenomenon? 2) Name the properties of alpha-keratins, especially the amino acid composition and structure of this protein. 3) Write a tripeptide, taking into account the peculiarities of the amino acid composition of alpha-keratins.

1) the woolen sweater/socks are consisting of alpha keratin, which has a secondary structure, stabilized by hydrogen bonds (they are relatively weak, breaking them causing the presence of water, which transforms the helical alpha structure of keratin and sinusoidal beta structure.)and inter-helical disulfide bridges. The amino acid composition of this a-keratin has a high (11%) content of cysteine ​​and hydrophobic amino acids. Происходит денатурирование структуры альфа-кератина и он теряет свою способность поддерживать форму ткани. 2)complete insolubility in water at pH 7.0 and physiological temperature. This property is partly due to the fact that the molecules contain a large percentage of hydrophobic amino acids residues (phenylalanine, isoleucine, valine, methionine and alanine). Due to the conformation of the protein, the R-group of these residues moves towards the outer helical structure of the molecule. Possesses high structural stability. 3)ala+leu+cys

The sequence and position of amino acids in trypsin, chymotrypsin, elastase and in some blood coagulation factors coincide by 40%. 1) Suggest what all these proteins might have in common. 2) Name the types of bonds in protein molecules. Write the formation of peptide and hydrophobic bonds. 3) Write a tripeptide consisting of aromatic and sulfur-containing essential amino acids and monoaminodicarboxylic acid

1) they are serine proteases - enzymes that cleave peptide bonds on proteins 2) Peptide , ionic, disulfide, hydrogen, hydrophobic bonds. A peptide bond is a chemical bond formed between two molecules when the carboxyl group of one molecule reacts with the amino group of the other molecule, releasing a molecule of water. Hydrophobic bonds in proteins arise as a consequence of the interaction of their hydrophobic amino acids with the polar solvent, water. 3) ala + дуг + metionine

In the biochemical laboratory, with partial hydrolysis of the protein and subsequent fractionation of peptides, peptides were obtained: А) gly—ala-val—leu-iso; B) tre-asp- lys— tyr-.glu 1) Name the compound most similar in properties to hydrocarbon molecules. Explain the answer. 2) Indicate the most soluble compound in a hydrophobic environment. Explain why. 3) Note the features of the behavior of these compounds in the biuret test, ninhydrin reaction, Fol's reaction and xanthoprotein reaction.

1)A - Because of the this amino acid include a lot of nonpolar amino acid and our hydrocarbon is also a nonpolar 2) A 3)Fol reactions occur because our amino acids include the cysteine and it means A and B does not happen if Fol. The xanthoproteic reaction is a method that can be used to detect a presence of protein soluble in a solution, using concentrated nitric acid. The test gives a positive result in amino acids carrying aromatic groups, especially in the presence of tyrosine. the test is positive the proof is neutralized with an alkali, turning dark yellow. The yellow colour is due to xanthoproteic acid which is formed due to nitration of certain amino acids, most common examples being tyrosine and tryptophan. B is will be positive A and B will show the positive test becausethe reagent does not in fact contain biuret ((H2N-CO-)2NH). The test is named so because it also gives a positive reaction to the peptide-like bonds in the biuret molecule

Malonate was added to the medium containing succinate and the enzyme succinate dehydrogenase (SDH). With an increase in the substrate concentration, the enzyme activity resumed. 1) What is the role of malonate in this reaction? Write the formulas for succinate and malonate. 2) What class, subclass does SDG belong to? Write the formula for his coenzyme. 3) Write a redox reaction involving SDH.

1)Malonic acid is the classic example of a competitive inhibitor of the enzyme succinate dehydrogenase (complex II), in the respiratory electron transport chain. It binds to the active site of the enzyme without reacting, competing with the usual substrate succinate but lacking the −CH2CH2− group required for dehydrogenation. This observation was used to deduce the structure of the active site in succinate deh7ydrogenase. Inhibition of this enzyme decreases cellular respiration 2) CLASS : oxireductase, subclass: dehydrogenase 3) succinate - fumarate

1.A patient with hypoacid gastritis showed a decrease pepsin activity in gastric juice. 1) To which class, subclass and subclass of enzymes does pepsin belong? 2) Write the reaction that the enzyme catalyzes? 3) Chemical nature, activator, optimum pH of this enzyme.

1)Pepsin belongs to the class of hydrolases, endopeptidases, peptidase subclass-hydrolysis of peptide bonds is carried out. 2)Pepsin is a globular protein with a molecular weight of about 34,500. The pepsin molecule is a polypeptide chain, which consists of 340 amino acids, contains 3 disulfide bonds and phosphoric acid. Pepsins are endoproteinases with an unusually acidic pH optimum (about pH 2). They cleave with the help of two aspartyl residues in the active center the peptide bonds of proteins,

.In acute pancreatitis, proteolytic enzymes (trypsin, chymotrypsin) are activated in the cells of the pancreas. To avoid autolysis of the pancreas (self-digestion of its own proteins) at the preclinical stage, complete starvation and cooling of the abdominal wall in the pancrea 8s are recommended. 1) How can you explain the need to use these measures? 2) What type of specificity is characteristic of pancreatic enzymes? 3) The mechanism of activation of trypsin and chymotrypsin.

1)Starvation leads to decrease in the production of enzyme that can damage pancreatic wall. Cooling reduces inflammation of pancreatic tissue 2)Group specificity - the enzyme will act only on molecules that have specific functional groups, such as amino, phosphate and methyl groups. For example: chymotrypsin and trypsin. 3)Enteropeptidase converts trypsinogen into its active form trypsin, resulting in the subsequent activation of pancreatic digestive enzymes. Under action of trypsin, peptide bond between amino acid in chymotrypsin is breaks and Pi-chymotrypsin. Then dipeptide bond of this molecule is cleaved that produce alpha-chymotrypsin. So, active chymotrypsin formed by these 3 polypeptide chains.

What color reactions can be used to prove non full value protein? 1) Which proteins named non- full-value? 2) What are essential amino acids? List all the essential amino acids. Write Formulas for Three Essential Amino Acids Hydrophobic Radicals. 3) Write a collagen fragment in the form of a tripeptide, taking into account the peculiarities of its amino acid composition. What are the structures of collagen?

Biuretic, Ninhydrin, Xanthoprotein, Million, Will 1)Defective proteins are proteins that lack certain amino acids that cannot be synthesized in the human body (essential amino acids). 2) Essential amino acids are amino acids that cannot be obtained in the human body by biosynthesis, therefore they must constantly come in the form of dietary proteins. Their absence in the body leads to life-threatening phenomena.valine, isoleucine, leucine, lysine, methionine, threonine, tryptophan and phenylalanine. VALINE, LEUCINE, ISOLEUCINE 3) The collagen molecule consists of three polypeptide chains, each of which contains approximately 1,000 amino acid residues, among which glycine dominates (33%). In addition to glycine, collagen contains a lot of alanine, proline, oxyproline and oxylysine. The secondary structure is a β-helix with a left-hand direction of rotation. Three such β-helices - tropocollagen -are combined into collagen fibers of different

A patient has acute viral hepatitis A (Botkin's disease). An increase in the activity of which enzyme (amylase, hexokinase, CPK, alanine aminotransferase, trypsin) in the blood will confirm the damage of hepatocytes? 1) Select one of the listed enzymes, name the class, subclass, sub-subclass. 2) The structure of this enzyme. 3) Write a catalyzed reaction

In acute viral hepatitis, an increase in ALT occurs even before the development of the clinical picture 1) alanine aminotransferase (ALT) - class: transferase, subclass: Transferring nitrogenous groups-transaminase, sub-subclass: transaminase (aminotransferase). 2) Aminotransferases consist of an apoenzyme and a coenzyme represented by phosphopyridoxal (H3PO4 + vitamin B6) 3) glutamate +pyruvate - a-ketoglutarate + alanine