Question

Choose the role(s) of HCl in digestion:

• A. Activates salivary amylase for hydrolysis of starch.
• B. Bactericidal properties.
• C. Activates rennin and pepsin.
• D. Provides perfect pH for absorption of Fe.

Answer 1

Answer: (B), (C), (D)

Provides perfect pH for absorption of Fe.

Oxyntic cells in the stomach are responsible for secretion of HCl. HCl deactivates salivary amylase as salivary amylase can't work at this pH. But HCl, on its own, breaks down starch. Also, pro-rennin and pepsinogen are pro-enzymes and they need to be activated for proper digestion of the food. These enzymes are in inactive form because they are proteases and can harm the stomach if they are always in the activated form. HCl converts these proenzymes into rennin and pepsin.