Here's a breakdown:

* Pepsin is produced in the stomach in its inactive form, pepsinogen. Hydrochloric acid (HCl) in the stomach activates pepsinogen into pepsin.

* Pepsin breaks down long protein chains into smaller peptides.

Other enzymes involved in protein digestion:

* Trypsin and chymotrypsin are produced in the pancreas and work in the small intestine. They further break down peptides into smaller units.

* Aminopeptidase and carboxypeptidase are also found in the small intestine and work on the ends of peptides, breaking them down into individual amino acids.

These enzymes work together in a coordinated process to completely digest protein, allowing the body to absorb and utilize the individual amino acids for growth, repair, and other essential functions.