Pepsin

Definition

First digestive enzyme of proteins, produced by the stomach in an acidic environment (pH 1.5-2), breaking down proteins into polypeptides.

How it works

Pepsin is produced in its inactive form (pepsinogen) by stomach chief cells and activated by hydrochloric acid. It functions only in a highly acidic environment and is responsible for initiating protein digestion. Pepsin breaks down complex proteins into smaller polypeptides, thereby facilitating the work of subsequent pancreatic proteases in the small intestine. Unlike popular belief, the stomach does not absorb digested proteins – it simply prepares them for intestinal absorption. Pepsin is inactivated in the small intestine where the pH becomes neutral.

Role

Initiating protein digestion by fragmenting them into polypeptides in the acidic gastric environment.

Examples

• Digestion of meat in the stomach
• Initial decomposition of an egg
• Fish fragmentation

Recommendations

Consume proteins with balanced meals for optimal digestion. Avoid eating immediately after very protein-rich meals. Maintain good gastric health for adequate pepsin production.

Key takeaway

Pepsin is the first key to protein digestion, acting in the acidic stomach.

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