Iso-enzymes……………………………………………………….………………………………………………….16

a. Phenol containing amino acids. b. Basic amino acids c. Acidic amino acids d. Non-essential amino acids. e. Essential amino acids ANS: e

15- All of the following about protein denaturation is true EXCEPT:

a. It is loss of primary, secondary, tertiary and quaternary structures. b. It causes loss of biological activity of proteins. c. Denaturated proteins are easily precipitated. d. Strong acids can cause protein Denaturation ANS: a

16- Cysteine, cystine and methionine are:

a. Essential amino acids b. Non-protein amino acids c. Acidic amino acids d. Sulfur containing amino acids

ANS: d

17- Elastin is:

a. Scleroprotein b. Chromoprotein c. Metaloprotein d. Phosphoprotein e. Glycoprotein ANS: a

18- Collagen is:

a. Insoluble in most protein solvents b. By boiling it gives gelatin c. Rich in glycine d. Very firm structure e. All of the above