Which organ is responsible for producing pepsin?

The stomach is responsible for producing pepsin, an important digestive enzyme. Pepsin is secreted as an inactive precursor known as pepsinogen by the chief cells located in the gastric glands of the stomach lining. When pepsinogen is exposed to the acidic environment created by gastric acid (hydrochloric acid), it gets activated into pepsin. This enzyme plays a crucial role in the digestion of proteins, breaking them down into smaller peptides.

In contrast, while the pancreas produces several digestive enzymes and is essential for digestion, it specifically secretes enzymes like amylase, lipase, and proteases into the small intestine, not pepsin. The liver is primarily involved in producing bile, which aids in fat digestion and metabolism rather than protein digestion. The small intestine is the site of further digestion and nutrient absorption but does not produce pepsin itself. Therefore, the stomach is the correct answer as it is the organ directly responsible for the production of pepsin.