Metabolism — MCQs Biology – T4Tutorials .PK

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1. Metabolism is the sum of:
(A) Only anabolic reactions
(B) Only catabolic reactions
(C) Catabolic and anabolic reactions
(D) Enzyme synthesis

2. Catabolic pathways:
(A) Build complex molecules from simple ones
(B) Do not produce energy
(C) Break down complex molecules to release energy
(D) Occur only in plants

3. Anabolic pathways:
(A) Do not require energy
(B) Release energy by breaking molecules
(C) Only occur in mitochondria
(D) Build complex molecules from simple ones

4. The main energy currency of the cell is:
(A) NADH
(B) FADH2
(C) ATP
(D) GTP

5. Glycolysis occurs in:
(A) Cytoplasm
(B) Mitochondrial matrix
(C) Nucleus
(D) Endoplasmic reticulum

6. The end product of glycolysis under aerobic conditions is:
(A) Pyruvate
(B) Lactate
(C) Acetyl-CoA
(D) Glucose

7. The end product of glycolysis under anaerobic conditions in humans is:
(A) Lactate
(B) Pyruvate
(C) Acetyl-CoA
(D) Ethanol

8. Pyruvate is converted to Acetyl-CoA by:
(A) Pyruvate kinase
(B) Pyruvate dehydrogenase complex
(C) Lactate dehydrogenase
(D) Hexokinase

9. Citric acid cycle occurs in:
(A) Mitochondrial matrix
(B) Cytoplasm
(C) Nucleus
(D) Golgi apparatus

10. The main purpose of the citric acid cycle is to:
(A) Produce ATP directly
(B) Store glucose
(C) Convert glucose to pyruvate
(D) Generate NADH and FADH2 for oxidative phosphorylation

11. The final electron acceptor in oxidative phosphorylation is:
(A) NAD+
(B) FAD
(C) Oxygen
(D) Pyruvate

12. Oxidative phosphorylation occurs in:
(A) Cytoplasm
(B) ER
(C) Nucleus
(D) Mitochondrial inner membrane

13. Substrate-level phosphorylation occurs in:
(A) Glycolysis and citric acid cycle
(B) Electron transport chain
(C) Beta-oxidation only
(D) Photosynthesis only

14. Gluconeogenesis is:
(A) Breakdown of glucose
(B) Formation of glucose from non-carbohydrate precursors
(C) Conversion of glucose to glycogen
(D) Glycolysis in reverse

15. Glycogenolysis refers to:
(A) Breakdown of glycogen to glucose-1-phosphate
(B) Synthesis of glycogen
(C) Formation of glucose from pyruvate
(D) Storage of glucose in liver

16. Glycogenesis refers to:
(A) Breakdown of glycogen
(B) Conversion of pyruvate to lactate
(C) Formation of glycogen from glucose
(D) Glucose oxidation

17. Fatty acid oxidation occurs in:
(A) Cytoplasm
(B) Mitochondrial matrix
(C) ER
(D) Nucleus

18. The main product of beta-oxidation of fatty acids is:
(A) Glucose
(B) Lactate
(C) Pyruvate
(D) Acetyl-CoA

19. Ketone bodies are produced in:
(A) Muscle
(B) Brain
(C) Liver
(D) Kidney

20. Lipogenesis occurs in:
(A) Muscle
(B) Brain
(C) Liver and adipose tissue
(D) Heart

21. Amino acid catabolism produces:
(A) Glucose only
(B) Ketone bodies only
(C) Fatty acids only
(D) Urea and intermediates for energy production

22. Urea cycle occurs in:
(A) Cytoplasm only
(B) Pancreas
(C) Kidney only
(D) Liver

23. The main function of pentose phosphate pathway is to:
(A) Produce ATP
(B) Store glucose
(C) Generate NADPH and ribose-5-phosphate
(D) Produce lactate

24. NADPH produced in pentose phosphate pathway is mainly used for:
(A) Energy production
(B) Biosynthetic reactions
(C) Electron transport
(D) Glycolysis

25. Fructose-1,6-bisphosphate is an intermediate of:
(A) Beta-oxidation
(B) Citric acid cycle
(C) Pentose phosphate pathway
(D) Glycolysis

26. ATP synthase produces ATP using:
(A) Substrate-level phosphorylation
(B) Glycolysis
(C) Proton gradient (chemiosmosis)
(D) Beta-oxidation

27. Enzymes that regulate metabolic pathways are often:
(A) Constitutive
(B) Inactive
(C) Allosteric and regulated
(D) Only in mitochondria

28. Hexokinase catalyzes:
(A) Phosphorylation of glucose to glucose-6-phosphate
(B) Conversion of pyruvate to acetyl-CoA
(C) Hydrolysis of glycogen
(D) Synthesis of glycogen

29. Phosphofructokinase-1 (PFK-1) is:
(A) A constitutive enzyme
(B) An allosteric enzyme regulating glycolysis
(C) Involved in gluconeogenesis only
(D) Lipid metabolizing enzyme

30. Pyruvate dehydrogenase is regulated by:
(A) Temperature only
(B) Substrate activation
(C) pH only
(D) Product inhibition by acetyl-CoA and NADH

31. Cori cycle connects:
(A) Urea cycle and glycolysis
(B) Glycolysis and citric acid cycle
(C) Lipid metabolism and amino acid metabolism
(D) Glycolysis in muscle with gluconeogenesis in liver

32. Glucagon primarily:
(A) Stimulates gluconeogenesis and glycogenolysis
(B) Stimulates glycolysis
(C) Inhibits glycogen breakdown
(D) Stimulates protein synthesis

33. Insulin primarily:
(A) Stimulates gluconeogenesis
(B) Stimulates lipolysis
(C) Stimulates glycogenesis and glucose uptake
(D) Inhibits glycolysis

34. Lipoproteins function to:
(A) Store glucose
(B) Transport lipids in the blood
(C) Metabolize amino acids
(D) Produce ATP

35. Acetyl-CoA is a common intermediate in:
(A) Lipid metabolism only
(B) Glycolysis only
(C) Carbohydrate, lipid, and protein metabolism
(D) Amino acid synthesis only

36. Glucose-6-phosphatase is found in:
(A) Liver and kidney
(B) Muscle only
(C) Adipose tissue only
(D) Brain only

37. Glycolysis yields a net of:
(A) 2 ATP per glucose
(B) 4 ATP per glucose
(C) 30 ATP per glucose
(D) 32 ATP per glucose

38. Citric acid cycle produces per acetyl-CoA:
(A) 2 NADH, 1 FADH2, 2 ATP
(B) 3 NADH, 1 FADH2, 1 ATP
(C) 3 ATP only
(D) 2 ATP only

39. Gluconeogenesis is favored during:
(A) Fed state
(B) Stress only
(C) Exercise only
(D) Fasting state

40. Fatty acid synthesis occurs in:
(A) Cytoplasm
(B) Mitochondria
(C) ER
(D) Nucleus

41. Lipolysis occurs in:
(A) Cytoplasm
(B) Adipose tissue
(C) Liver only
(D) Muscle only

42. Glycerol from triglycerides can enter:
(A) Urea cycle
(B) Citric acid cycle
(C) Glycolysis
(D) Pentose phosphate pathway

43. Amino acids can be converted to:
(A) Glucose
(B) All of the above
(C) Ketone bodies
(D) Fatty acids

44. Urea is excreted to remove:
(A) Fatty acids
(B) Ketone bodies
(C) Carbohydrates
(D) Nitrogen from amino acid catabolism

45. Cori cycle helps:
(A) Remove lactate from muscle
(B) Produce ATP in liver only
(C) Convert glucose to fatty acids
(D) Stimulate gluconeogenesis only in muscle

46. ATP yield from complete oxidation of 1 glucose molecule is approximately:
(A) 2 ATP
(B) 36 ATP
(C) 30-32 ATP
(D) 40 ATP

47. NADH from glycolysis yields how many ATP in mitochondria?
(A) 2.5 ATP
(B) 1-2 ATP
(C) 3 ATP
(D) 4 ATP

48. FADH2 from citric acid cycle yields approximately:
(A) 2.5 ATP
(B) 1.5 ATP
(C) 3 ATP
(D) 4 ATP

49. AMP activates:
(A) Hexokinase
(B) Phosphofructokinase-1 (PFK-1)
(C) Pyruvate kinase
(D) ATP synthase

50. Citrate inhibits:
(A) PFK-1
(B) Hexokinase
(C) Pyruvate kinase
(D) ATP synthase