Biological oxidation……………………………………………………………………………………………..55

38- The following are basic essential amino acids EXCEPT:

a. Histidine b. Lysine c. Arginine d. Leucine

ANS: d

39- The bonds present in the primary structure of proteins

a. Hydrogen bonds b. Peptide bonds c. Disulfide bonds d. Electrostatic bonds e. All of the above ANS: b

40- A newborn has milky white skin, white hair, and red appearing eye color. This disorder most often results from a defect in which of the following enzymes? Select one:

a. Tyrosinase b. Phenylalanine hydroxylase c. Dihydrofolate reductase d. NADPH oxidase e. Homogentisic acid oxidase ANS: a

41- The pigment melanin: Select one:

a. Always contains Sulphur derived from cysteine b. Is formed from tryptophan c. Is present in skin in order to absorb UV radiation to protect underlying structures d. Is formed in albinos ANS: c

42- Histamine, a chemical mediator of allergies and anaphylaxis, is synthesized from which amino acid Select one:

a. Ornithine b. Arginine c. Glutamic acid d. Histidine ANS: d