Answer Happy

48. Study the following table and determine which enzyme has the greatest affinity for its substrate Enzyme El 62 E3 E4 a. El b. E2 c. E3 d. E4 Substrate EIS E₂S E,S E4S 49. Pepsin characteristically cleaves the peptide bonds of non-terminal amino acids, therefo pepsin is correctly classified as a (an): a. reductase b. kinase c. endopeptidase d. exopeptidase Km (M) 1.1 x 10-5 0.9 x 109 2.7 x 10-2 0.4 x 10- 50. Diabetes mellitus may result in hypertriglyceridemia due to increased: a. glycolysis b. glycogenesis c. gluconeogenesis d. glycogenolysis 51. A competitive inhibitor has the following effect on a Limeweaver-Burke (double reciprocal) Plot. a. It moves the entire curve to the right b. It moves the entire curve to the left c. It changes the y-intercept d. It changes the x-intercept e. It has no effect on the slope

52. A non-competitive inhibitor of an enzyme catalyzed reaction: a. decreases Ven b. is without effect at saturating substrate concentrations. c. can actually increase reaction velocity in rare cases. d. The first and second choices are both correct. 53. A competitive inhibitor of an enzyme is usually: a. a highly reactive compound. b. a metal ion such as Hg² or Pb² c. structurally similar to the substrate. water insoluble. d. c a poison 54. The degree of inhibition a by a competitive inhibitor is obtained from a. measurement of Va b. measurement of the y-intercept on a Limeweaver-Burke Plot. c. measurement of KM d. crystallographic studies. e. is unrelated to the binding affinity of the inhibitor to the enzyme. 55. An allosteric inhibitor of an enzyme usually a. binds to the active site. b. participates in feedback regulation. c. denatures the enzyme. d. causes the enzyme to work faster. e. is a hydrophobic compound. 56. Histidine is degraded to a-ketoglutarate and is described as a a. gluco amino acid b. glucogenic amino acid c. ketogenic amino acid d. keto-gluco amino acid 57. Which of the following amino acids is considered as both ketogenic and glucogenic? a. Valine b. Tryptophan c. Lysine d. None of these 13

58. An example of a transamination process is a. glutamate = hexanoic acid + NH3 b. aspartate + hexanoic acid = glutamate + oxaloacetate c. aspartate + a ketoglutarate= glutamate + oxaloacetate d. glutamate a-ketoglutarate + NH3 59. A person suffering from phenylketonuria on consumption food containing high phenylalanine may lead to the accumulation of: a. Phenylalanine b. Phenylpyruvate c. Tyrosine d. Isoleucine 60. Oxidative deamination is the conversion of an amino a. group from an amino acid to a keto acid b. acid to a carboxylic acid plus ammonia c. acid to a keto acid plus ammonia d. group from an amino acid to a carboxylic acid