Protein Digestion Starts in the Stomach

Steps:

• Food enters the mouth for mechanical breakdown and carbohydrate digestion via salivary amylase.
• It travels through the esophagus to the stomach.
• In the stomach, gastric juice containing hydrochloric acid activates pepsinogen into pepsin.
• Pepsin begins breaking peptide bonds in proteins into smaller polypeptides.

Why C is correct:

• The stomach secretes pepsin, the first enzyme to hydrolyze proteins, initiating their digestion.

Why the others are wrong:

• A: Mouth handles starch digestion with amylase, not proteins.
• B: Esophagus only transports food; no enzymes act here.
• D: Small intestine continues protein digestion with trypsin but does not start it.

Final answer: C