SOLVED

11)Which of the following residues acts as a general-base catalyst in the cleavage of the C3-C4 bond in the mechanism of the aldolase-catalyzed reaction? A)Methionine B)Histidine C)Cysteine D)Asparagine E)Lysine 12)Which of the following residues acts as a general-acid catalyst in aldolase but as a general-base catalyst in chymotrypsin? A)Methionine B)Histidine C)Cysteine D)Asparagine E)Lysine 13)In which of the following classes of reactions is a coenzyme required? A)oxidation reactions B)two carbon transfer C)acyl transfer D)reduction reactions E)A, B, and D 14)Which of the following statements best describes what cofactors are? A)They are metal ions that assist enzymes in carrying out their catalytic reactions. B)They are organic molecules that assist enzymes in carrying out their catalytic reactions. C)They are organic molecules called coenzymes. D)They are organic molecules derived from compounds commonly known as vitamins. E)all of the above 15)Which of the following statements is not true of coenzymes? A)Coenzymes catalyze chemical reactions similar to enzymes. B)Coenzymes may function as oxidizing and reducing agents. C)Coenzymes play a variety of chemical roles exactly like those played by the amino acid side chains of enzymes. D)Coenzymes may function as nucleophiles or strong bases needed in a reaction. E)Coenzymes may function as activators needed in a reaction. 16)Which of the following is not a lipid-soluble vitamin? A)vitamin A B)vitamin D C)vitamin E D)vitamin C E)vitamin K 17)Which of the following vitamins is the only water-soluble vitamin that does not function as a coenzyme? A)vitamin B12 B)riboflavin (B2) C)vitamin C D)thiamine (B1) E)pyridoxine (B6) 18)Which of the following vitamins can be synthesized by all mammals except humans and guinea pigs? A)vitamin B12 B)riboflavin (B2) C)vitamin C D)thiamine (B1) E)pyridoxine (B6) 19)Which type of vitamins, water-soluble or lipid-soluble, can we overdose on? 20)Which of the following vitamins are radical inhibitors or antioxidants? A)niacin B)vitamins B1 and B12 C)vitamins B2 and B6 D)vitamins A and D E)