• facebook
  • whatsapp
  • telegram

 ENZYMES

1. Assertion (A): Almost all enzymes are proteins.
    Reason (R): Most of the enzymes are polymers of amino acids.
A: A and R are correct. R explains A.

 

2. First name of enzyme
A: Ferments

 

3. The term enzyme was coined by
A: Willy Kuhne

 

4. Match the following.

List - I  List - II
I) Enzyme A) First discovered enzyme
II) Precursor of enzyme B) Louis Pasteur
III) Zymase C) Zymogen
IV) Ferments D) Protein

Correct matching is
      I        II        III        IV
A: D       C        A         B

 

5. The term ferments was coined by
A: Louis Pasteur

 

6. An enzyme has
1) Primary structure            2) Tertiary structure      

  3) Secondary structure       4) All
A: 4(All)

 

7. The similarity between enzymes and inorganic catalysts is that both are
A: Concerned with bringing change in the velocity of a chemical reaction  without under
     going any permanent change

 

8. Assertion (A): Enzymes are universal.
     Reason (R): They are present in all organisms which show sexuality.
A: A and R are correct. R explains A.

 

9. The definition of enzyme was given by
A: Dixon, Web

 

10. The source of first enzyme discovered is
A: Yeast

 

11. Assertion (A): All enzymes are proteins.
      Reason (R): Nucleic acid like 23s rRNA can act as enzyme.
A: A is false. R is correct.

 

12. Assertion (A): Enzyme is a polymer of amino acids.
       Reason (R): Chemically enzymes are proteins.
A: A and R are correct. R explains A.

 

13. Find out mismatch.
       1) First essay on enzyme - J.B.S. Haldane
       2) First enzyme crystallised - Urease
       3) First enzyme discovered - Zymase
       4) First name of the enzyme - Zymogen
A: 4(First name of the enzyme - Zymogen)

 

14. Match the following.

List - I List - II
I) Enzyme A) Polymer of Amino acids
II) Ribozyme B) Chromogenic substrate
III) Taq polymerase C) RNA
IV) β − Galactosidase D) Thermostable

 Correct matching is
        I         II         III        IV
A:   A        C         D         B

 

15. A functional enzyme shows
A: Tertiary structure

 

16. Generally enzyme gets damaged at this temperature
A: Above 40oC

 

17. Read the following statements and find out incorrect one.
       1) Enzymes are hydrophilic colloidals.
       2) Water becomes vapour. It is a physical reaction.
       3) When bonds are broken and new bonds are formed, it is a chemical reaction.
       4) None
A: 4(None)

 

18. Number of carbonic acid molecules formed from water and CO2 in the presence and absence
       of carbonic anhydrase respectively are
A: 21,60,000, 200 per hour


19. Substrate + Enzyme give
A: Product + Enzyme

 

20. Substrate occupies into the active site of enzyme by the following process.
A: Diffusion

 

21. Read the following statements and find out incorrect one.
       1) Acleft or pocket in the 3-D structure of a catalytic protein into which substrate fits is
           called as active site.
       2) A protein is an enzyme.
       3) Enzymes are macromolecules.
       4) Enzymes are colloidal.
A: 2(A protein is an enzyme.)

 

22. Read the following statements.
       1) Same substrate can undergo different types of reactions and each catalysed by a 
            separate enzyme.
       2) The last step in enzyme action is the release of product from enzyme.
       3) Between substrate and product unstable intermediate structural states are formed.
       4) Enzyme reduce the energy for biochemical reaction.
A: 4(Enzyme reduce the energy for biochemical reaction.)

 

23. If E = Enzyme, S = Substrate and P = Product. Choose the following equation for action
        of enzyme on the substrate to form a product
A: E + P [ES] [EP] E + S

 

24. Formation of (ES) complex was first explained by
A: Emil Fisher

 

25. Geometry of the enzyme is altered in the hypothesis of
A: Daniel E. Koshland

 

26. Tertiary structure of enzyme is altered by the factors like (A) substrate concentration
        (B) pH (C) temperature. The following graph is suitable to X = ?
A: BC

27. Assertion (A): High temperature destroys enzymatic activity.
       Reason (R): Low temperature preserves the enzyme in a temporarily inactive state.
A: A and R are correct. R do not explains A.

 

28. Km value is
       1) 

       2) Approximate inverse measures of affinity of the enzyme for a given substrate
       3) Michaelis - Menten constant
       4) All
A: 4(All)

 

29. Malonate is similar to
A: Succinic acid

 

30. Competitive inhibitors which occupy active site on enzyme surface
A: Competitive inhibitors

 

31. Physically enzymes are
A: Colloidals

 

32. Assertion (A): Enzymes are heat sensitive.
       Reason (R): They are colloidals.
A: A and R are correct. R explains A.

 

33. Assertion (A): Enzymes are almost inactive at lower temperature.
       Reason (R): They are denatured at lower temperature.
A: A is correct. R is false.

 

34. Protein nature of the enzyme was first established by
A: Sumner

 

35. Match the following.

List − I List − II
I) Optimum temperature A) 25 − 30oC
II) Low temperature B) Denatured
III) High temperature C) Sensitive
IV) Heat D) Less active 

       A     B     C      D
A:  I      III    IV      II

36. Assertion (A): Enzymes speed up the rate of a reaction.
       Reason (R): Enzymes change the equilibrium of a reaction.
A: A is correct. R is false.

 

37. Assertion (A): Food kept in refrigerator is not spoiled.
      Reason (R): Very cold temperature keeps the enzyme in a permanently inactive state
A: A is correct. R is false.

 

38. Read the following statements and find out incorrect one.
       1) Enzymes are specific in action.
       2) Generally enzymes are polymers.
       3) Most of the enzymes work at neutral pH.
       4) All enzymes are reversible in their action.
A: 4(All enzymes are reversible in their action.)

 

39. Co-enzymes are
       1) metals                                      2) small organic molecules
       3) small inorganic molecules       4) large inorganic molecules
A: small organic molecules

 

40. The following are regenerated
A: Coenzyme

 

41. Enzymes are
A: hydrophilic

 

42. The cell free enzyme that participates in fermentation is
A: Zymase

 

43. Match the following.

List − I List − II
I) Haem A) Carboxylase
II) Niacin B) Catalase
III) Zinc C) IAA Oxidase
IV) Mn D) NADP
  E) Peptidase

  The correct matching is
       I      II       III       IV
A:  B     D       A        C

 

44. Match the following.

List − I List − II
I) Peroxidase A) Molybdenum
II) Carboxy peptidase B) Haem
III) Urease C) Nickel
IV) Nitrogenase D) Zinc
  E) Copper

    The correct matching is
          I       II       III       IV
A:     B      D        C       A

 

45. Metal ions of the enzymes are concerned with
       A. To form co-ordination bonds with side chains at the active site.
       B. To form one or more co-ordination bonds with the substrate.
       1) Neither A nor B          2) B           3) A           4) A and B
A: A and B

 

46. Protein part of the holoenzyme is called
A: Apoenzyme

 

47. Assertion (A): Enzymes enhance the rate of the reaction.
       Reason (R): Enzymes lower the activation energy.
A: A and R are correct. R do not explains A

 

48. Match the following.

List − I List − II
I) Cofactor A) Polymer of amino acids
II) Coenzyme  B) Non protein constituent of holoenzyme
III) Apoenzyme C) Organic compound tightly bound to apoenzyme
IV) Prosthetic D) Organic compounds transiently associated with Apoenzyme.

  Correct matching is
      I       II       III       IV
A:  B     D       A        C

49. Assertion (A): Coenzymes are cofactors.
       Reason (R): All cofactors are not prosthetic groups.
A: A and R are correct. R do not explains A.

 

50. Prosthetic group is a
A: Part of active site of holoenzyme

 

51. Turn Over Number (TON) indicates
Ans: Number of substrate molecules converted to products.

 

52. Turn Over Number indicates
Ans: nature of substrate

 

53. To calculate the turn over number of an enzyme the following data is not necessary
       1) Number of products            2) Number of substrate molecules
       3) Time taken                           4) Moles of enzymes
Ans: Number of products

 

54. The following is a vitamin
       1) NADP        2) FAD         3) NAD         4)Niacin
Ans: Niacin

 

55. The E.C. of Glucose-6-Phosphotransferase is
Ans: 2.7.1.2

 

56. The first number in E.C. must be
Ans: less than 7

 

57. The second number in E.C. is always
       1) above 3       2) less than 13      3) less than 14      4) 1, 3
Ans: 4 (1, 3)

 

58. Enzyme code is
       1) 4 digit number      2) Decided by I.U.B.      3) Permanent       4)All
Ans: 4 (All)

 

59. Read the following statements and find out incorrect one.
       1) All the enzymes discovered so far are divided into 6 classes.
       2) IUB means International Union of Biochemistry.
       3) Enzyme classification is based on the type of chemical reactions they catalyse.
       4) Competitive inhibitor closely resembles the substrate in its molecular structure.
Ans: 4 (All the enzymes discovered so far are divided into 6 classes.)

 

60. Malonate resembles
Ans: Succinate

 

61. Assertion (A): Catalytic activity is lost when cofactor is removed from the enzyme.
       Reason (R): Cofactor is non-protein part of the enzyme.
Ans: A and R are correct. R do not explains A.