Where does the digestion of proteins primarily take place?

The primary site for the digestion of proteins is the stomach. In the stomach, the enzyme pepsin, which is activated by the acidic environment created by gastric acid, begins the process of breaking down protein molecules into smaller peptides. The acidity of the stomach also helps to denature the proteins, making them more accessible to enzymatic action.

While the duodenum and jejunum are important for overall digestion and absorption, the significant enzymatic digestion of proteins initiated in the stomach continues in the duodenum with the help of pancreatic enzymes. However, it is the stomach where the actual conversion of protein to peptide fragments initially occurs. The ascending colon is primarily involved in the absorption of water and electrolytes rather than protein digestion. Thus, the stomach is recognized as the primary organ where protein digestion begins.