The chemical digestion of protein begins in the stomach. When food enters the stomach, it encounters gastric juices, which contain hydrochloric acid and the enzyme pepsin. These components work together to break down the protein molecules into smaller peptides.
Hydrochloric acid creates an acidic environment, which is essential for pepsin to function efficiently. Pepsin starts the process of protein breakdown by cleaving the peptide bonds linking the amino acids. As the proteins are digested in the stomach, they are further processed into smaller peptide chains, which are then released into the small intestine for further digestion.
In summary, chemical digestion of protein begins in the stomach, where it is facilitated by gastric juices that include hydrochloric acid and pepsin, effectively transforming complex proteins into simpler forms that can be absorbed by the body.