16. Disulfide bonds most often stabilize the native structure of

A. extracellular proteins
B. dimeric proteins
C. hydrophobic proteins
D. intracellular proteins

17. Secondary structure in protein refers to

A. linear sequence of amino acids joined together by peptide bond
B. three dimensional arrangement of all amino acids in polypeptide chain
C. regular folding of regions of the polypeptide chain
D. protein made up of more than one polypeptide chain

18. Heme is the binding pocket of myoglobin and hemoglobin and is composed of

A. negatively charged residues
B. polar residues
C. hydrophobic residues
D. positively charged residues

19. What is the effect of a decrease in pH on hemoglobin oxygen affinity?

A. Decrease in oxygen affinity
B. Increase in oxygen affinity
C. No effect on oxygen affinity
D. Increase affinity in muscle cell otherwise decrease

20. What is the proportion of glycine residues in collagenous regions?

A. One-fourth
B. One-third
C. Half
D. One-tenth