11th Class Biology Unit 5 Enzymes MCQs with Answers

1.What roles does nicotinamide adenine dinucleotide play in oxidative pathways?

2.The enzymes that catalyse the reactions in which two molecules are joined together by synthesis of new bonds, using energy from ATP, are placed in group;

3.Which of the following is an example of hydrolases?

4.Which of the following statements about enzymes is correct?

5.Enzyme B requires Zn+2 to catalyse the conversion of substrate X. The zinc is best identified as a(n):

6.If an enzyme solution is saturated with substrate, the most effective way to obtain an even faster yield of products would be:

7.How does a non-competitive inhibitor decrease the rate of an enzyme-catalysed reaction?

8.Which enzyme class is responsible for catalysing the addition of water to a substrate molecule?

9.Enzymes speed up chemical reactions by lowering:

10.Rate of enzyme catalyzed reactions are _________ times greater than uncatalyzed reaction rates:

11.All enzymes are synthesized inside cells by:

12.The enzymes of glycolysis are present in:

13.The enzymes of Calvin cycle and Krebs's cycle

14.Enzymes are _________ globular proteins

15.Small cleft or depression in the surface of globular enzyme is:

16.Substrate molecule fits into binding site by weak chemical forces such as:

17.At which region of active site, substrate is transformed into products?

18.The non-protein components of enzyme are called:

19.The kinds or types of co-factor are:

20.The protein part of enzyme is called:

21.The complete enzyme including its coenzyme or prosthetic group is termed as:

22.The cofactors which are attached with enzyme by covalent bonds are called:

23.Prosthetic groups are attached with enzyme by:

24.When the co-factor is a non-protein organic molecule and is loosely attached with enzyme, it is called:

25.Co-enzymes participate in enzyme-catalyzed reactions, often by transporting:

26.The most important coenzyme in a cell is the hydrogen acceptor:

27.When food is oxidized in cell, enzymes draw electrons from food molecules and transfer them to:

28.The speed of a chemical reaction depends on the amount of:

29.The energy which works to destabilize existing chemical bonds is called:

30.Which of the following is correct about enzymes?

31.Catalytic site is activated when:

32.Activation energy is lowered by:

33.The mechanism of enzyme can be summarized as:

34.In complex metabolic pathways, end products formed inhibit (through feedback) the:

35.Lock and key model of enzyme mechanism was proposed by:

36.Emil Fischer proposed that,

37.Lock and key model was proposed by Emil Fischer in:

38.The induced fit model was modified form of lock and key model was proposed by:

39.Whick of the following represent induced fit model?

40.Identify the model:

41.Which of the following can affect enzyme activity?

42.Which of the following can be affected by temperature in an enzyme?

43.The temperature at which an enzyme works at its maximum rate is called

44.The optimum temperature for human enzymes is:

45.When the temperature of body falls below 37.0°C the bonds that determine enzymes shape becomes:

46.The enzymes of thermophilic bacteria can function at:

47.The loss of globular shape of enzyme is called:

48.A slight increase or decrease in pH of an enzyme causes:

49.The pH at which an enzyme works at maximum rate is called:

50.Pepsin works its best in:

51.The enzyme papain is present in:

52.Papain works in:

53.Pepsin's optimum pH is:

54.7.0 is the optimum pH of:

55.At unlimited substrate concentration at a specific time, rate of reaction directly depends on:

56.If enzyme concentration goes on increasing, and rate of reaction stays constant and does not increase further means that:

57.What does the middle arrow indicate?

58.A chemical that interferes and block an enzyme's activity is called:

59.Which of the follow is a potent inhibitor of prostaglandin?

60.Pick up the irreversible inhibitor:

61.Which inhibitors are used as antibiotics to kill bacteria?

62.Which of the following is structurally similar with succinic acid?

63.A none competitive inhibitor binds to:

64.In feedback inhibition, the final product inhibits:

65.The enzyme which uses ATP to join molecules is:

66.The mechanism of enzyme inhibition, used to understand the factors that influence enzyme activity is called:

67.Reversible inhibitors make ____ bonds with enzymes:

68.Penicillin permanently disables the enzymes responsible for building bacterial cell walls because it acts as:

69.Succinic acid and CoA react to form succinyl CoA which is catalysed by: succinyl-CoA:

70.The phenomenon where the products of a process controls the process itself, often limiting the production of more products is called:

71.The enzymes which remove or add H+ ions or electrons from substrate are called:

72.Which of the following is NOT a hydrolase

73.The enzymes catalyse the non-hydrolytic addition or removal of groups from substrates are:

74.The enzyme which catalyses the conversion of glucose to fructose is:

75.Which enzyme breakdown small polypeptides into dipeptides?

76.Which enzyme is responsible for the breakdown of DNA?

77.Choose the correct class:

78.Pick the enzyme which is not related to others:

79.The reaction indicates.

80.Mark the disaccharide

Unit 5: Unit 5: Enzymes — Mcqs