MINISTRY OF EDUCATION AND SCIENCE OF UKRAINE
UZHHOROD NATIONAL UNIVERSITY
FACULTY OF MEDICINE
DEPARTMENT OF BIOCHEMISTRY AND PHARMACOLOGY
Biochemistry test bank
Part 2. Metabolism of major classes of
biomolecules. Molecular biology and genetics.
Self-preparation manual for medical students
Uzhhorod – 2022
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,УДК 577.1(075.8)=111
Упорядники:
- зав. кафедри біохімії та фармакології медичного факультету ДВНЗ «УжНУ», к.мед.н., доц.
Ростока Лариса Михайлівна,
- асистент кафедри біохімії та фармакології медичного факультету ДВНЗ «УжНУ» Бурмістрова
Яна Юріївна
- асистент кафедри біохімії та фармакології медичного факультету ДВНЗ «УжНУ» Сіткар
Андрій Дмитрович
Методична розробка для студентів складено у відповідності з вимогами освітньо-професійної
програми підготовки магістра.
РЕЦЕНЗЕНТИ:
Фабрі З.Й. – д.б.н., професор кафедри біохімії та фармакології медичного факультету ДВНЗ
«УжНУ»
Сірчак Є.С. – д.мед.н., професор, зав. кафедри пропедевтики внутрішніх хвороб медичного
факультету ДВНЗ «УжНУ»
Затверджено на засіданні Вченої ради медичного факултету ДВНЗ «УжНУ»
від 26.04.2022 р., протокол №6.
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, FOREWORD
In order to improve the preparation of students of higher medical educational institutions
for practical classes in biochemistry and better understending of theoretical material, test
bank in the discipline have been arranged. This manual provides tests of following topics:
metabolism of major classes of biomolecules (carbohydrates, lipids, amino acids,
nucleotides) and its regulation, fundamentals of molecular biology and molecular genetics.
The tests are divided into five chapters, each of which includes tasks of different types of
difficulty: multiple choice questions, theoretical questions, situational tasks and questions of
higher difficulty levels. It is important that the organization of situational tasks is related to
clinical cases and practical medicine.
Biological chemistry is a fundamental medical discipline. A perfect understanding of the
theoretical material is the basis for the study of clinical disciplines, interpretation of
laboratory parameters and future medical practice.
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, Chapter I. Carbohydrate metabolism and its regulation.
List of the exam questions:
1. Carbohydrates – definition and classification. List the functions of carbohydrates.
Structure and biological role of mono-, di- and polysaccharides and their derivatives.
2. The digestion and absorption of carbohydrates. Lactose intolerance.
3. Glycolysis – definition, biological role. Glycolysis reactions, the preceding stage and
the glycolytic oxidation-reduction stage. Regulation of glycolysis.
4. The anaerobic and aerobic degradation of glucose - definition, energy balance. Lactate
dehydrogenase reaction. Shuttle mechanisms. The Pasteur effect.
5. Gluconeogenesis – definition, biological role. Irreversible reactions of glycolysis.
Bypassed reactions of gluconeogenesis. Cory cycle. Noncarbohydrate precursors of
gluconeogenesis.
6. Glycogen metabolism and its regulation. Glycogen storage diseases.
7. Pentose phosphate pathway, its biological role and regulation. Drug-induced
hemolytic anemia. Sorbitol pathway.
8. Metabolism of fructose and galactose. Hereditary fructose intolerance. Galactosemia.
9. Regulation of blood glucose level. Disturbances of hormonal regulation of
carbohydrate metabolism. Diabetes mellitus. Hypoglycemia.
10.Glycoproteins and proteoglycans, their biological role. Mucopolysaccharidoses.
Multiple Choice Questions:
1. People, who for a long time remained in D. Creatine kinase reaction
hypodynamic state, develop intense pain in the muscles E. Cyclase reaction
after a physical exertion. What is the most likely cause of
this pain? 4. When blood circulation in the damaged tissue is
A. Accumulation of lactic acid in muscles restored, lactate accumulation stops and glucose
B. Intensive breakdown of muscle proteins consumption decelerates. These metabolic changes are
C. Accumulation of creatinine in muscles caused by activation of the following process:
D. Decreased content of lipids in muscles A. Aerobic glycolysis
E. Increased content of ADP in muscles B. Anaerobic glycolysis
C. Lipolysis
2. Blood test of the patient revealed albumine content of D. Gluconeogenesis
20 g/l and increased activity of lactate dehydrogenase E. Glycogen biosynthesis
isoenzyme 5 (LDH5). These results indicate disorder of
the following organ: 5. Untrained people often have muscle pain after sprints
A. Liver as a result of lactate accumulation. This can be caused by
B. Kidneys intensification of the following biochemical process:
C. Heart A. Glycolysis
D. Lungs B. Gluconeogenesis
E. Spleen C. Pentose phosphate pathway
D. Lipogenesis
3. Human red blood cells contain no mitochondria. E. Glycogenesis
What is the main pathway for ATP production in these
cells? 6. Diseases of respiratory system and circulatory
A. Anaerobic glycolysis disorders impair the transport of oxygen, thus causing
B. Aerobic glycolysis hypoxia. Under these conditions the energy metabolism is
C. Oxidative phosphorylation carried out by anaerobic glycolysis. As a result, the
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,following substance is generated and accumulated in aspartate aminotransferase, creatine phosphokinase. In
blood: what organ (organs) is the development of a pathological
A. Lactic acid process the most probable?
B. Pyruvic acid A. In the heart muscle (initial stage of myocardium
C. Glutamic acid infarction)
D. Citric acid B. In skeletal muscles (dystrophy, atrophy)
E. Fumaric acid C. In kidneys and adrenals
D. In connective tissue
7. 6 hours after the myocardial infarction a patient was E. In liver and kidneys
found to have elevated level of lactate dehydrogenase in
blood. What isoenzyme should be expected in this case? 13. As a result of exhausting muscular work a worker
A. LDH1 has largely reduced buffer capacity of blood. What acidic
B. LDH2 substance that came to blood caused this phenomenon?
C. LDH3 A. Lactate
D. LDH4 B. Pyruvate
E. LDH5 C. 1,3-bisphosphoglycerate
D. 3-phosphoglycerate
8. Researchers isolated 5 isoenzymic forms of lactate E. -
dehydrogenase from the human blood serum and studied
their properties. What property indicates that the 14. A 7-year-old girl has signs of anemia. Laboratory
isoenzymic forms were isolated from the same enzyme? examination revealed pyruvate kinase deficiency in
A. Catalyzation of the same reaction erythrocytes. What process disturbance plays the main
B. The same molecular weight role in anemia development?
C. The same physicochemical properties A. Anaerobic glycolysis
D. Tissue localization B. Oxidative phosphorylation
E. The same electrophoretic mobility C. Tissue respiration
D. Peroxide decomposition
9. Some students developed myodynia after continuous E. Amino acids desamination
physical activity during physical education. The reason
for such condition was accumulation of lactic acid in the 15. Desulfiram is widely used in medical practice to
skeletal muscles. It was generated in the students’ bodies prevent alcocholism. It inhibits aldehyde dehydrogenase.
after activation of the following process: Increased level of what metabolite causes aversion to
A. Glycolysis alcochol?
B. Gluconeogenesis A. Acetaldehyde
C. Pentose-phosphate cycle B. Ethanol
D. Lipolysis C. Malonyl aldehyde
E. Glycogeny D. Propionic aldehyde
E. Methanol
10. After a sprint an untrained person develops muscle
hypoxia. This leads to the accumulation of the following 16. The high level of Lactate Dehydrogenase (LDH)
metabolite in muscles:
isozymes concentration showed the increase of LDH-1
A. Lactate and LDH-2 in a patient’s blood plasma. Point out the
B. Ketone bodies most probable diagnosis:
C. Acetyl CoA
A. Myocardial infarction
D. Glucose 6-phosphate
E. Oxaloacetate B. Skeletal muscle dystrophy
C. Diabetes mellitus
11. Cytoplasm of the myocytes contains a lot of D. Viral hepatitis
dissolved metabolites resulting from glucose oxidation. E. Acute pancreatitis
Name the metabolite that turns directly into lactate:
A. Pyruvate 17. A patient presents with hypoxia. What metabolic
B. Oxaloacetate process activates when oxygen supply is insufficient?
C. Glycerophosphate A. Anaerobic glycolysis
D. Glucose-6-phosphate B. Urea cycle
E. Fructose-6-phosphate C. Pentose-phosphate pathway
D. Oxidative decarboxylation of keto acids
12. A patient presents high activity of LDH1,2,
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,E. Tricarboxylic acid cycle D. Br-
E. Cl-
18. A patient was found to have an increased blood
serum LDH-1 activity. In which organ is the pathological 24. A 58-year-old man is brought to emergency after he
process localized? was found unconscious. Examination of patient revealed
A. Heart general weakness, hypoglycemia, blood pH = 7,24.
B. Liver Hypoglycemia is likely related to his alcohol use.
C. Kidneys Excessive intake of ethanol increases the ratio:
D. Stomach A. NADH/NAD+
E. Muscles B. NADPH/NADP+
C. NAD+/NADH
19. Under anaerobic conditions during glycolysis ATP D. FADH2/FAD
is synthesized by the way of substrate phosphorylation. E. E. FAD/FADH2
This process uses energy of other highenergy compounds.
Specify one of such compounds: 25. Under anaerobic conditions ATP are synthesized.
A. Phosphoenol pyruvate ATP is produced by the process of:
B. Glucose 6-phosphate A. Substrate phosphorylation
C. Lactate B. Oxidative phosphorylation
D. Pyruvate C. Photosynthetic phosphorylation
E. Glucose D. Transfer of phosphate group from fructose-
bisphosphate upon ADP
20. Red blood cells for proper function need energy in E. Deamination of amino acids
form of ATP. What process provides the red blood cell
with required amount of ATP? 26. Lactate dehydrogenase is an oligomeric molecule
A. Anaerobic glycolysis which contains the next number of subunits:
B. Aerobic oxidation of glucose A. Four
C. Tricarboxylic acid cycle B. Three
D. в-oxidation of fatty acids C. Two
E. Pentosophosphate pathway D. Six
E. Eight
21. During consumption of cakes or sweets in mixed
saliva a transient increase in lactate level takes place. 27. Which of the following statements about the
Activation of what biochemical process causes this glycolytic intermediate, fructose-6- phosphate is correct?
effect? A. In glycolysis fructose-6-phosphate is an aldol
A. Anaerobic glycolysis but is not itself split by the aldol reaction until
B. Tissue respiration phosphorylated to fructose-1:6-bisphosphate
C. Aerobic glycolysis B. In glycolysis fructose-6-phosphate is converted
D. Gluconeogenesis to glucose-6-phosphate and can then be split by the aldol
E. Microsomal oxidation reaction into an aldehyde and a ketone
C. In glycolysis fructose-6-phosphate is an aldol so
22. Glycolysis - a universal pathway in the living cell. once phosphorylated to fructose-1:6-bisphosphate cannot
The enzymes of glycolysis are located in the: be split by the aldol reaction into an aldehyde and a
A. Cytoplasm of every living cell ketone
B. Cytoplasm of red blood cell only D. In glycolysis fructose-6-phosphate is formed
C. Mitochondria of striated muscle cell from glucose-6-phosphate and is split by the aldol
D. Nuclei of liver cells reaction into an aldehyde and a ketone
E. Lysosomal vesicles E. -
23. The enzyme pyruvate kinase catalyses the transfer 28. Glucokinase can be characterized by one of the next
of high energy phosphate from phosphoenol pyruvate to statements:
ADP. Pyruvate kinase requires __ ions for maximum A. It has a much higher Michaelis constant (Km)
activity: for glucose than does hexokinase
A. Mg2+ B. ATP is activator of this enzyme
B. Ba2+ C. The reaction that this enzyme catalyses produces
C. Fe2+ a high energy phosphate
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,D. It is the major regulatory enzyme of glycolysis B. Citric acid
E. It is located in mitochondria C. Glycogen
D. Succinic acid
29. Most of the reactions of glycolysis are reversible. E. Acetoacetic acid
However, the three steps are irreversible. Specify these
enzymes: 35. Chose the correct statement of phosphofructokinase
A. Hexokinase, phosphofructokinase and pyruvate properties:
kinase A. AMP is an activator of this enzyme
B. Pyruvate kinase, phosphoglycerate kinase, B. The reaction that this enzyme catalyzes produces
phosphoglycerate mutase a high energy phosphate bond without the involvement of
C. Phosphofructokinase, phosphohexose isomerase, ADP or ATP
enolase C. It is not regulatory enzyme of glycolysis
D. Glucokinase, enolase, phosphoglycerate mutase D. The substrate of this enzyme is glucose-6-
E. Phosphohexose isomerase, phosphoglycerate phosphate
mutase, hexokinase, E. This enzyme catalyzes the interconversion of
dihydroxyacetone phosphate and glyceraldehydes-3-
30. One mole of glucose in glycolytic pathway in phosphate
anaerobic conditions produces:
A. Two moles of lactate 36. Alcoholic fermentation occurs in yeast and several
B. Three moles of lactate bacterial species. In this process product of pyruvate
C. Four moles of lactate decarboxylation is:
D. One moles of lactate A. Acetaldehyde
E. Five moles of lactate B. Ethanol
C. Lactate
31. In some anaerobic bacteria the pyruvate produced D. Phosphoenolpyruvate
by glycolysis is converted to the ethyl alcohol (alcoholic
E. Glucose
fermentation). What is the biological significance of this
process?
37. Which of the following is a substrate for aldolase
A. NAD+ replenishment
activity in glycolytic pathway?
B. Lactate production
A. Fructose-1,6- bisphosphate
C. ADP production
B. Glucose-1,6-bisphosphate
D. Providing the cells with NADPH
C. Glucose-6-phosphate
E. ATP production
D. Fructose-6-phosphate
E. Glyceraldehyde-3-phosphate
32. Which of the following enzyme-catalysed reactions
has a product containing a newly formed high energy
phosphate bond?
38. The oxidation of lactic acid to pyruvic acid requires
the following vitamin derivative as the hydrogen carrier:
A. 2-Phosphoglycerate to phosphoenolpyruvate
A. NAD+
B. 3-Phosphoglycerate to 2-phosphoglycerate
B. FAD
C. The phosphorylation of glucose
C. FMN
D. Dihydroxyacetone phosphate to glyceraldehydes
phosphate
D. Coenzyme A
E. Fructose-1,6-bisphosphate→to→glyceral-
E. Lithium pyrophosphate
dehydes-3-phosphate→and dihydroxyacetone phosphate
39. Glycolysis is also referred to as:
33. The following is an enzyme required for glycolysis: A. Embden-Meyerhof-Parnas pathway
A. Pyruvate kinase B. Lineweaver-Burk pathway
B. Pyruvate dehydrogenase C. Krebs-Henseleit pathway
C. Pyruvate carboxylase D. Chargaff pathway
D. Glucose-6-phosphatose E. Watson-Crick pathway
E. Glycerokinase
40. The combination of subunits in lactate
dehydrogenase molecule makes it possible to create the
34. As a result of anaerobic glycolysis glucose is
next number of isoenzymes:
converted to:
A. Lactic acid
A. Five
B. Four
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, C. Six normal circumstances by erythrocytes and by muscle
D. Three cells during intense exercise is recycled through liver in
E. Eight the Cori cycle. The metabolite is:
A. Lactate
41. Which of the following enzymes is not involved in B. Alanine
glycolysis: C. Oxaloacetate
A. Glucose oxidase D. Glycerol
B. Glucokinase E. NADH
C. Hexokinase
D. Aldolase 48. A 24-year-old man presented with symptoms of
E. Enolase shortness of breath, weakness and fatigue. His
hemoglobin level was 7g/dl. Red blood cell isolated from
42. Anaerobic oxidation of glucose to lactate is the patient showed abnormally low-level of lactate. A
regulated by appropriate enzymes. What enzyme is the deficiency of which of the following enzymes would be
major regulator of this process? the most likely cause for patient’s anemia?
A. Phosphofructokinase A. Pyruvate kinase
B. Enolase B. Glucokinase
C. Glucose-6-phosphate isomerase C. Hexokinase
D. Lactate dehydrogenase D. Phosphofructokinase
E. Aldolase E. Phosphoglucose isomerase
43. During glycolysis fructose-1,6-bisphosphate is 49. Which out of the following enzymes cleaves a
decomposed by the enzyme: carbon-carbon bond in the pathway of glycolysis?
A. Aldolase A. Aldolase
B. Hexokinase B. Glyceraldehyde-3-phosphate dehydrogenase
C. Enolase C. Enolase
D. Fructokinase D. Phosphoglycerate mutase
E. Disphosphofructophosphatase E. Phosphoglycerate kinase
44. Which mammalian cell does not have aerobic 50. Phosphoglycerate kinase functions in carbohydrate
pathway of glucose catabolism? metabolism to produce ATP via: A. Substrate level
A. Red blood cell phosphorylation
B. Nerve cell B. Oxidative phosphorylation
C. Sperm cell C. Oxidative decarboxylation
D. Ovum D. Phosphorolysis
E. Liver cell E. Oxidative deamination
45. The irreversible reactions of glycolysis include that 51. A 7-year-old child presents with marked signs of
catalyzed by: hemolytic anemia. Biochemical analysis of erythrocytes
determined low concentration of NADPH and reduced
A. Phosphofructokinase
glutathione. What enzyme is deficient in this case leading
B. Phosphohexose isomerase
to the biochemical changes and their clinical
C. Fructose-bisphosphate aldolase manifestations?
D. Glyceraldehyde-3-phosphate dehydrogenase A. Glucose-6-phosphate dehydrogenase
E. Phosphoglycerate kinase B. Hexokinase
C. Fructokinase
46. In yeast cells occurs a process which is similar to D. Pyruvate kinase
glycolysis - alcohol fermentation. In course of this
E. Lactate dehydrogenase
process through several stages from pyruvate is produced:
A. Ethanol
52. A patient, who has been subsisting exclusively on
B. Acetaldehyde
polished rice, has developed polyneuritis due to thiamine
C. Lactate deficiency. What substance is an indicator of such
D. Pyruvate avitaminosis, when it is excreted with urine?
E. Glyceraldehyde A. Pyruvic acid
B. Malate
47. The major metabolic product produced under
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