Gastric juice contains pepsin, a crucial enzyme for protein digestion.
Understanding Pepsin's Role in Digestion
Pepsin is not directly secreted into the stomach; instead, it's released as an inactive precursor called pepsinogen by chief cells in the stomach lining. The conversion of pepsinogen to its active form, pepsin, is triggered by the acidic environment created by hydrochloric acid (HCl), secreted by parietal cells. This low pH (highly acidic) environment is essential for pepsin's function. Once activated, pepsin begins breaking down proteins into smaller peptides, initiating the process of protein digestion.
- Pepsinogen: Inactive precursor.
- Hydrochloric Acid (HCl): Activates pepsinogen.
- Pepsin: Active enzyme; breaks down proteins.
This process is a key step in the overall digestive process, ensuring that proteins from our food are broken down into smaller components that can be absorbed by the body. Without pepsin, protein digestion would be significantly impaired.
The reference material states that "Pepsin is a stomach enzyme that serves to digest proteins found in ingested food. Gastric chief cells secrete pepsin as an inactive zymogen called pepsinogen." This highlights the importance of pepsinogen activation by the acidic environment of the stomach.
