Question

Where does the protein digestion occur?

• A. Stomach
• B. Ileum
• C. Rectum
• D. Duodenum

Answer 1

The correct option is A

Stomach

The correct option is A.

Explanation of the correct option:

1. Stomach is a highly muscular elastic bag located below the diaphragm.
2. Stomach secretes certain enzymes which mainly facilitate the digestion of proteins.
3. The inner linings of the stomach secrete gastric juice which contains the enzyme pepsin.
4. Oxyntic cells secreted by the epithelium lining of the stomach secrete $\mathrm{HCl}$ which activates pepsinogen into pepsin.
5. Pepsin digests proteins into peptides.
6. Another enzyme rennin found in the stomach acts on casein (milk protein) to convert it into paracaesin (insoluble peptide).

Final Answer: The protein digestion occurs in stomach.