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5.1 Glycolysis β Test 1
Q1. When the [NADH]/[NADβΊ] ratio is high, which metabolic pathway can take place?β Lactic acid formation
Q2. Which is the best method to study glycolytic fluxes in a cancer cell?β Tracing of radiolabelled carbon
Q3. Lactate is formed by active skeletal muscle when the rate of glycolysis exceeds the rate of:β Oxidative metabolism
Q4. Aerobic oxidation of glucose or fructose releases 32 ATP. How many ATP are generated upon complete breakdown of sucrose?β 64
Q5. Which enzyme converts glucose to ethanol (alcoholic fermentation)?β Zymase
Q6. The net equation for aerobic glycolysis is:β Glucose + 2ADP + 2Pi + 2NADβΊ β 2 pyruvate + 2ATP + 2NADH + 2HβO + 4HβΊ
Q7. In glycolysis, which enzyme converts fructose-1,6-bisphosphate to glyceraldehyde-3-phosphate (and DHAP)?β Aldolase
Q8. How does fructose-2,6-bisphosphate affect PFK-1 and fructose-1,6-bisphosphatase-1 (FBPase-1)?β Increases PFK-1 and decreases FBPase-1
Q9. In some organisms, the potent allosteric activator of phosphofructokinase-1 is:β Fructose-2,6-bisphosphate
Q10. Glucose-6-phosphate and glyceraldehyde-3-phosphate are processed by glycolysis. How many ATP are generated respectively from each?β 3 ATP and 2 ATP
Q11. The reaction catalyzed by which of the following enzymes yields an ATP molecule?β Phosphoglycerate kinase
Q12. The enzyme that catalyzes the conversion of 2-phosphoglycerate to phosphoenolpyruvate is:β Enolase
Q13. In the EmbdenβMeyerhof pathway, 2-phosphoglyceric acid is converted to phosphoenolpyruvic acid by:β Enolase
Q14. Glyceraldehyde-3-phosphate dehydrogenase:β Has a free βSH group and requires NADβΊ
Q15. Glyceraldehyde-3-phosphate dehydrogenase enzyme (variant):β Has a free βSH group at its active site and requires NADβΊ
Q16. If glucose labelled with ΒΉβ΄C at position C1 is added to a bacterial culture anaerobically, which carbon of lactic acid is labelled?β The methyl carbon
Q17. If glucose labelled at both C1 and C4 with ΒΉβ΄C is used, where is the radioactivity found in pyruvate?β Both the second and third carbons
Q18. Hexokinase phosphorylates glucose. The phosphorylation process:β Prevents escape of glucose from the cell
5.1 Glycolysis β Test 2
Q19. In glycolysis, ultimately:β Glucose is converted to pyruvic acid
Q20. Which of the following does NOT happen during glycolysis?β Formation of glucose in the cytosol is called substrate-level phosphorylation
Q21. Which of the following does NOT happen during glycolysis? (variant)β One GTP is also formed
Q22. If one glucose molecule is metabolized, the net output of glycolysis is:β 2 pyruvate, 4 ATP and 2 NADH
Q23. The end products of glycolysis include ATP,:β NADH and pyruvate
Q24. Which of the following is an allosteric regulatory enzyme of the glycolytic pathway?β Phosphofructokinase
Q25. Which is a correct sequence of reactions in glycolysis?β Glucose-6-P β fructose-1,6-bisP β glyceraldehyde-3-P
Q26. Which is a correct sequence of reactions in glycolysis? (variant)β Glucose-6-phosphate β fructose-1,6-bisphosphate β glyceraldehyde-3-P
Q27. In anaerobic glycolysis, 2 moles of inorganic phosphate are used per mole of glucose. Which enzyme catalyzes the uptake of inorganic phosphate?β Glyceraldehyde-3-phosphate dehydrogenase
Q28. In muscle, when ATP demand is high and oxygen is short, which dehydrogenase catalyzes the oxidation of NADH?β Lactate dehydrogenase
Q29. In muscle, when ATP demand is high and oxygen is in short supply, which dehydrogenase oxidizes NADH? (variant)β Lactate dehydrogenase
Q30. The end products of anaerobic respiration in humans are:β Lactic acid
Q31. Which of the following are the end products of anaerobic respiration in humans? (variant)β Lactic acid
Q32. During lactic acid fermentation, the net yield of ATP and NADH per mole of glucose is:β 2 ATP and 0 NADH
Q33. In glucose metabolism, lactate dehydrogenase reduces pyruvate to lactate while oxidizing:β NADH to NADβΊ
Q34. The steps of glycolysis between glyceraldehyde-3-phosphate and 3-phosphoglycerate involve all of the following EXCEPT:β Oxidation of NADH to NADβΊ
Q35. Which glycolytic intermediate is a high-energy compound whose oxidation energy is trapped as phosphate?β Phosphoenolpyruvate (PEP)
Q36. The primary rate-limiting enzyme in glycolysis is:β Phosphofructokinase
5.1 Glycolysis β Test 3
Q37. Which one of the following is a regulatory enzyme of glycolysis?β Phosphofructokinase
Q38. The enzymes that have a greater effect on the rate of the overall pathway are called regulatory enzymes. Which is a regulatory enzyme of glycolysis?β Phosphofructokinase
Q39. The major site of regulation of glycolysis is at:β Phosphofructokinase
Q40. The glycolytic pathway requires one or more allosteric regulatory enzymes. Which is one?β Phosphofructokinase
Q41. High levels of ATP inhibit glycolysis through inhibition of which regulatory enzyme?β Phosphofructokinase
Q42. Which statements about inhibitors of PFK-1 are correct? 1) ATP & citrate 2) Citrate & fructose-2,6-bisphosphate 3) ATP & malate 4) ATP & fructose-2,6-bisphosphateβ 1 & 3 correct
Q43. Which statement about phosphofructokinase-1 is FALSE?β It is inhibited by AMP
Q44. The end product of glycolysis in the RBC (red blood cell) is:β Lactic acid
Q45. Hypoxia stimulates glycolysis in the RBC by which event?β Release of glycolytic enzymes from band 3 protein on the RBC membrane
Q46. Which of the following steps in glycolysis is reversible?β Glucose-6-phosphate β fructose-6-phosphate
Q47. Which enzyme carries out a reversible reaction in glycolysis?β Phosphoglycerate kinase
Q48. Formation of 3-phosphoglyceric acid from 1,3-bisphosphoglyceric acid by phosphoglycerate kinase is an example of:β Substrate-level phosphorylation
Q49. How many ATP molecules are formed when sucrose is metabolized during glycolysis by substrate-level phosphorylation?β 4
Q50. Which enzyme is preferentially expressed in cancer cells and plays a crucial role in altered glucose metabolism?β Pyruvate kinase M2 (PKM2)
Q51. When yeast is used in baking, the dough rises due to the COβ produced by the enzyme:β Pyruvate decarboxylase
Q52. In anoxic conditions during flooding, plant ATP is generated through:β Fermentation
Q53. A bacterial cell performing anaerobic respiration (fermentation) has 20 molecules of glucose. How many ATP are produced?β 40
Q54. Which metabolic process in mammalian cells does NOT occur in the mitochondria?β Glycolysis