Question

Protein digesting enzyme is
A)Pepsin
B)Ptyalin
C)Amylase
D)Maltase
E)Sucrase

Answer 1

Hint: Pepsin is an endopeptidase which breaks down proteins into smaller peptides. It is formed in the main cells of the stomach lining and is one of the main digestive enzymes in the digestive processes of humans and many other species, where it helps digest proteins in food.

Complete answer:
Ptyalin is salivary amylase which helps in digestion of ripe and cooked starch in mouth.
Amylase is found in saliva as well as pancreatic juice and helps in breakdown of carbohydrates into simpler forms.
Maltase is an enzyme (disaccharidase) present in intestinal juice. It is responsible for breakdown of maltose into glucose subunits.
Sucrase acts on sucrose to give glucose and fructose subunits.

Pepsin is processed in the stomach and is one of the key digestive enzymes that helps food digest proteins. Zymogenic cells or peptic cells are pepsinogen and chymosin-containing gastric cells. The inactive pepsinogen is converted to the active enzyme pepsin, a proteolytic enzyme in the intestine, when subjected to hydrochloric acid. Pepsin converts proteins and peptones into proteins and (peptides). Polypeptide chain proteins are hydrolyzed by Pepsin and protein digestion is initiated. Pepsin is also an enzyme that digests protein.

Hence, the correct answer is option (A)

Note: It is responsible for absorption of just around 15% of the dietary protein. In the absence of pepsin, protein digestion is not hindered because other proteases are available. Pepsin acts under the highly acidic conditions of the intestine. It has an optimal pH of approximately 1.5. On the other hand, trypsin acts in the small intestine, part of which has a pH of about 7.5.