Questions

1. Phosphorylation of glucose by hexokinase does not contribute to:-

a) Escaping of glucose molecule out of cell.

b) Binding energy of phosphohexose isomerase.

c) Activation of glucose molecule.

d) Net negative free energy change.

2. Inhibition of Triose phosphate isomerase results in net formation of how many ATP from 1 molecule of glucose in glycol sis:

a) 4 b) 2 c) 0 d) 1

3. During glycolysis, 1 molecule of glucose yield how many molecules of H₂O:

a) 1 b) 2 c) 4 d) 0

4. During vigorous exercise, inhibition of lactate dehydrogenase in muscle does not result in:

a) High [NAD⁺] level b) lowering of pH

[NADH]

c) Inhibition of glycoysis d) shifting of equilibrium of bicarbonate buffer toward left

5. How many steps of glycolysis are endergonic in nature:-

a) 4 b) 6 c) 3 d) 2

6. The methyl group of pyruvate is formed from which carbon of glucose

a) 1 and 6 b) 2 and 5 c) 3 and 4 d) 2 and 4

7. If all the oxygen atoms of glucose were radioactively labeled, how many oxygen atom of pyruvat would be radioactive.

a) 3 b) 2 c) 1 d) None

8. Decyclization occurs in which step of glycolysis.

a) 5 b) 4 c) 3 d) 6

9. The phosphate group of glucose – 6 – phosphate is used in substrate level phosphorylation in step no. :

a) 7 b) 6 c) 10 d) 9

10. Which carbon of glucose occur in reduced state in pyruvate

a) 1 and 6 b) 2 and 5 c) 3 d) 4

11. Mannose enters glycolysis after it is converted to:

a) glycose – 6 – phosphate b) Fructose – 6 – phosphate

c) Fructose 1, 6 bisphosphate d) glucose – 1 – phosphate

12. UMP donor during conversion of galactose 1 – phosphate to UDP – glactose is

a) UTP b) UDP c) UDP – glucose d) UDP – mannose

13. No. of NADH consumed during conversion of 1 molecule of galactose to 2 molecule of pyruvate

a) 2 b) 1 c) 0 d) 3

14. Production of ethanol is inhibited by:

a) High [NADH] ratio b) presence of Mg²⁺

[NAD ⁺]

c) High CO₂ level d) presence of O₂

15. Which carbon of glucose is released as CO₂ during ethanol production?

a) 4 and 3 b) 1 and 6 c) 2 and 5 d) 3 and 5

16. Which enzymes doesn’t require Thiamine pyrophosphate

a) Pyruvate dehydcogenase b) pyruvate decarboxylase

c) Transketolase d) Succinate dehydrogenase

17. No. of ATP equivalents used in formation of 1 molecule of glucose from 2 molecule of pyruvate is

a) 4 b) 5 c) 6 d) 8

18. the most exergonic step during gluconeogenesis is

a) 1^st b) 2^nd c) 5^th d) 9^th

19. After 3 molecules of glucose – 6 – phosphate enter pentose phosphate pathway, how many molecules of CO₂ is liberated

a) 6 b) 3 c) 0 d) None

20. Defect in pentose phosphate pathway causes:-

a) Bromolecules damage by superoxide radical b) Reduced nucleotide, RNA, DNA brosynthesis

c) Both a & b d) Only a

21. Transketolase transfer how many carbon

a) 1 b) 2 c) 3 d) 4

22. Transaldolase transfer how many carbon

a) 1 b) 2 c) 3 d) 4

23. Which ractive species causes maximum damage to biomolecules

a) O₂ b) H₂O₂ c) OH^- d) OH

24. How many net ATP is used in converting glucose to pyruvate and pyruvate black to glucose.

a) 2 b) 4 c) 6 d) 8

25. Significance of lactate formation is/are

a) Prevent halting of glycolysis b) provede substrate for gluconeogenesis in liver

c) Increase [NAD⁺] ratio d) All

[NADH]

26. The final catabolic product of glucose in RBC is:

a) CO2 & H2O b) Pyruvate & lactafe c) Both a & b

27. The energy yielding pathway in RBC is

a) TCA cycle b) glycolysis c) both a & b d) pentose phosphate pathway

28. In cancerous cell much of ATP is formed by

a) TCA cycle b) glycolysis c) electron transport change d) Both a & b

29. The reactive intermediate in thiamine pyrophosphate catalysed reaction is

a) Carbocation b) Carbanion c) free radical d) All

30. In anaerobic process, there is …………………………………..of the carbons of glucose.

a) net oxidation b) net reduction c) no net oxidation or reduction

31. (α 1 → 6) glucosidase activity of debranching enzyme produce

a) glucose 1 – phosphate b) glucose – 6 – phosphate c) glucose d) glucose 1, 6 bisphosphate

32. The active residue in the phosphoglucomutase enzyme that catalyse the reaction is

a) Serine b) Threonine c) phosphorylated serine d) phosphorylated threonine

33. Glucose transporter in liver is

a) GLUT 4 b) GLUT 2 c) GLUT 1 d) All

34. Inhibition of Pi (inorganic phosphate) transporter at Endoplasmic reticulum of liver cell results in

a) Decrease level of glucose transport from liver to blood.

b) Lowers ATP concentration in liver cytosol

c) Decrease the activity of glyceraldehye 3 – phosphate dehydrogenase enzyme.

d) All

35. Glucose – 6 – phosphatase of liver is located at

a) cell membrane b) Mitochondrial inner membrane

c) cytosol d) membrane of endoplasmic reticulum

36. Which amino acid catalyse the initial attack reaction in glucogenin

a) Serine b) Threonine c) Tryptophan d) Tyrosine

37. The predominant hexokinase in liver in liver is

a) Hexokinase I b) Hexokinase II c) Hexokinase III d) Hexokinase IV

38. Which of the hexkinase have high Km value

a) Hexokinase I b) Hexokinase II c) Hexokinase III d) Hexokinase IV

39. Activity of hexokinase IV is inhibited by

a) glucose – 6 – phosphate b) glucose 1 – phosphate c) fructose – 6 phosphate d) All

40. Km of phosphofructose kinase I………………………….at high [ATP] ratio.

[ADP]

a) Increases b) Decreases d) Remain same

41. Inactivation of pyrucate kinase by phosphorylation in liver occurs when

a) Blood glucose level is high b) Glucoagon level in blood is high

c) Pyruvate level is high in cytosol d) All

42. Which of the following isn’t allosteric inhibitor of muscle pyruvate kinase?

a) Pyruvate b) Alanine c) ATP d) Acetyl coA

43. Fructose 2, 6 Bisphosphate lowers the Km value of which enzyme

a) phosphofructose kinase I b) Fructose 1, 6 bisphosphatase

c) Fructose 2, 6 bisphosphatase d) Phsphofructose kinase - 2

44. Fructose 2, 6 bisphosphate is formed when

a) Insulin level is high b) Glucose level in blood is low

c) Energy demand in liver cell is low d) TCA cycle intermediate don’t participate in biosynthesis reaction

45. Which of the following isn’t covalently attached with enzyme

a) FAD b) NAD⁺ c) lipoate d) Thiamin pyrophosphate

46. Which carbons of glucose are released as CO₂ when pyruvate is converted to Acetyl CoA.

a) 1 and 6 b)5 and 2 c) 4 and 3 d) 2 and 4

47. Avidin a protein in raw egg binds biotin and inhibits its absorption. Which enzyme activity may be inhibited when Avidin is intake?

a) pyruvate dehydroginase b) pyruvate carboxylase c) succinate dehydrogenase d) All

48. Pyruvate dehydrogenase complex is present in

a) cell membrane b) cytosol c) Mitochondria d) Endoplasmic reticulum

49. Lipoate is attached to with amino acid residue of Dihyropoyl transacetylase

a) His b) Lys c) phe d) Ser

50. No. of total electrons released when 1 molecule of glucose is converted to 2 molecule of Acetyl Coa

a) 2 b) 4 c) 8 d) 10