Question

What is the function of HCl during the digestion process?

• A. To activate pepsinogen
• B. To decrease the activity of pepsin enzymes.
• C. To create a neutral environment in the stomach.
• D. All of the above

Answer 1

The correct option is A To activate pepsinogen

The secretions of the stomach are collectively called gastric juice. It is produced by gastric glands. The gastric juice contains hydrochloric acid (HCl), pepsinogen, mucus, and bicarbonates. HCl is produced in the stomach by oxyntic cells (parietal cells) while chief cells produce pepsinogen. Pepsinogen is activated into pepsin by the action of HCl. The HCl present in the stomach creates an acidic environment since its pH is about 1.8. The acidic nature of HCl activates the inactive pepsinogen and converts it into an active enzyme. Pepsin then breaks down complex protein molecules present in food in simple protein molecules.
Alkaline mucus is secreted by mucus cells that prevents epithelial lining of the stomach from wearing off (called gastric excoriation) by HCl. Argentaffin cells and gastrin or G cells are collectively called enteroendocrine cells that are responsible for hormonal secretions in the stomach.
The different cells present in the gastric glands are depicted in the figure below: