31.What digestive enzyme would be most affected in people who are unable to produce hydrochloric acid?

a.pepsin

b.transaminase

c.pancreatic protease

d.intestinal peptidase

32.What is the chief function of pepsin?

a.to emulsify dietary proteins

b.to activate hydrochloric acid

c.to activate pancreatic proteases

d.to cleave proteins into smaller polypeptides

33.Pepsinogen is also known as which of the following compounds?

a.a zymogen

b.an oligopeptide

c.a postenzyme

d.a cofactor for pancreatic enzymes

34.Which of the following describes the structure of pepsin?

a.lipid

b.protein

c.nucleic acid

d.carbohydrate

35.Your cousin Wanda has a genetic defect causing lack of intestinal villus tripeptidases and dipeptidases. Which of the following digestive processes would be affected?

a.protein ? oligopeptides

b.peptides ? amino acids

c.amino acids ? peptides

d.polypeptides ? tripeptides

36.Protein-hydrolyzing enzymes are commonly known as which of the following?

a.proteases

b.hydrolyzers

c.zymogens

d.denaturases

37.What is the function of a protease?

a.to hydrolyze proteins

b.to synthesize proteins

c.to hydrolyze ribosomes

d.to synthesize ribosomes

38.How much of the dietary protein is hydrolyzed in the mouth?

a.0 percent

b.5–10 percent

c.15–20 percent

d.25–30 percent

39.Which of the following products are absorbed into the circulation after digestion of proteins?

a.free amino acids only

b.free amino acids and oligo-peptides only

c.free amino acids and dipeptides only

d.free amino acids, and a few dipeptides and tripeptides

40.What is the usual fate of orally ingested enzyme supplements?

a.digestion by gastrointestinal proteases

b.rapid degradation by salivary secretions

c.nearly complete absorption in original form from stomach

d.complete absorption in original form from jejunum