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4.1 Introduction β Test 1
Q1. Trypsinogen is converted into active trypsin by:β Enterokinase
Q2. Pancreatic lipase acts upon:β Fats
Q3. Pepsin is an example of a/an:β Enzyme
Q4. Which enzyme is released in its zymogen form?β Trypsin
Q5. Which enzymatic reaction produces a chromogenic product?β Phosphatase with para-nitrophenyl phosphate
Q6. Aldolase converts fructose-1,6-bisphosphate to G3P and DHAP. It belongs to:β Lyases
Q7. The natural source of bromelain, a cysteine endopeptidase, is:β Pineapple
Q8. Which enzyme has four variants, each with a metal centre of Cu-Zn, Mn, Fe or Ni?β Superoxide dismutase
Q9. Acetyl-CoA carboxylase belongs to which enzyme class?β Ligases
Q10. Variant enzymes that differ structurally but not functionally and are encoded by different alleles of the same locus are:β Alloenzymes
Q11. Pyridoxal phosphate is a cofactor required for:β Aminotransferase reactions
Q12. Which amino acid CANNOT act as a nucleophile in enzyme catalysis?β Asparagine
Q13. Which one of the following is NOT a hemoprotein?β Bilirubin oxidase
Q14. Which enzyme contains biotin?β Pyruvate carboxylase
Q15. Which enzyme contains biotin? (repeat)β Pyruvate carboxylase
Q16. Which ion is necessary for the activation of carbonic anhydrase?β Zinc
Q17. Ion necessary for carbonic anhydrase activation (repeat):β Zinc
Q18. The reaction rate catalysed by carbonic anhydrase is about:β 10βΆ molecules COβ per second
Q19. A small organic non-protein molecule that carries chemical groups between enzymes is a:β Coenzyme
Q20. A coenzyme is:β A vitamin (derivative) that acts with an enzyme
Q21. What happens to an enzyme when it denatures?β The shape of the enzyme molecule is changed
Q22. Which enzyme requires NADβΊ as a cofactor?β E. coli DNA ligase
Q23. Lipase, alkaline phosphatase, Ξ±-amylase and purine nucleosidase all hydrolyse their substrates. What is the first digit of the EC number for each?β 3,3,3,3
Q24. Which proteolytic enzymes are basic endoproteases?β Trypsin and chymotrypsin
Q25. Which proteolytic enzymes are basic endoproteases? (repeat)β Trypsin and chymotrypsin
4.1 Introduction β Test 2
Q26. Most metabolic enzymes operate:β Below saturation and below Kβ
Q27. Specificity of an enzyme is determined by:β Functional groups of the enzyme and its cofactors
Q28. The specificity of an enzyme is determined by (repeat):β Functional groups of the enzyme and its cofactors
Q29. Match the enzyme with its substrate:β i-4, ii-1, iii-2, iv-3
Q30. Enzyme-substrate interactions are predominantly:β All of the above
Q31. Which is NOT a flavoprotein?β Glyceraldehyde-3-phosphate dehydrogenase
Q32. Which coenzyme is NOT involved in group transfer?β NADβΊ
Q33. Isoenzymes are:β Oligomeric proteins with different properties catalysing the same reaction
Q34. Which one of the following has isoenzymes?β Lactate dehydrogenase
Q35. Isozymes differ in their:β All of these
Q36. Isozymes are:β Enzymes catalysing the same reaction with different physical properties
Q37. Which is a substrate-specific enzyme?β Lactase
Q38. Which exists as isoenzymes in humans?β Lactate dehydrogenase
Q39. The LDH variant predominantly found in brain is:β LDH3
Q40. The primary location of the LDH-1 isoenzyme is:β Heart muscle
Q41. Which one of the following breaks an ester bond?β Lipase
Q42. Lipases act between which pH range?β 5-7
Q43. Which enzyme is NOT part of a multienzyme complex?β Alcohol dehydrogenase
Q44. Which coenzyme is also called a co-substrate of an enzyme?β NADβΊ
Q45. The correct statement about oxidases is that they:β Do not incorporate oxygen into the product
Q46. The enzyme that directly transfers and incorporates oxygen into a substrate is a/an:β Oxygenase
Q47. An enzyme shows highest activity at pH 2-3, ~50% at pH 4, ~1% at pH 7. Which residue state is most responsible?β Protonated Asp
Q48. Tandem enzymes have two different activities on the same polypeptide. Which is an example?β PFK-2 / fructose-bisphosphatase-2
4.1 Introduction β Test 3
Q49. Match the protease with its mechanistic class:β i-1, ii-2, iii-3, iv-4
Q50. Which enzyme contains bound pyridoxal phosphate?β Alanine transaminase
Q51. Which enzyme does NOT contain bound pyridoxal phosphate?β Pyruvate dehydrogenase
Q52. Which enzyme contains bound pyridoxal phosphate? (variant)β Alanine transaminase
Q53. Which enzyme has bound thiamine pyrophosphate (TPP)?β Pyruvate decarboxylase
Q54. Reductases are enzymes that:β Add hydrogen to a substrate
Q55. Which coenzyme is involved in enzymatic reduction reactions?β NADPH
Q56. Which coenzyme is involved in enzymatic reduction reactions? (repeat)β NADPH
Q57. ____ is a catalyst (a catalytic biomolecule).β Ribozyme
Q58. Which amino acid can act as a nucleophile in enzyme catalysis?β Serine
Q59. Syntymes (synthetic enzyme mimics) can be developed by:β All of the above
Q60. Which statement is correct?β Phosphofructokinase-2 is a tandem enzyme
Q61. Which minerals function as prosthetic groups in enzymes?β Cobalt, copper and selenium
Q62. Trypsin is active in which pH range?β 7.5 to 8.5
Q63. Substrate binding in trypsin's specificity pocket is facilitated by which residue?β Aspartic acid
Q64. Trypsin hydrolyses peptide bonds at the:β C-terminal of Lys
Q65. Trypsin hydrolyses the peptide bond at the (repeat):β C-terminal of Lys
Q66. The enzyme first obtained in crystalline form was:β Urease
Q67. Which enzyme does NOT require ZnΒ²βΊ as a cofactor?β Trypsin
Q68. Enzymes produced in an inactive form in living cells are called:β Proenzymes
Q69. The term 'zymogen' refers to:β An inactive enzyme precursor
Q70. The metal ion present in alcohol dehydrogenase is:β ZnΒ²βΊ