THORAX ABDOMEN AND PELVIS

Detailed explanation-1: -Protein digestion begins in the stomach with the action of an enzyme called pepsin. Pepsin is the active protein-digesting enzyme of the stomach. When pepsin acts on the protein molecule, it breaks the bonds that hold the protein molecule together, called peptide bonds.

Detailed explanation-2: -The enzyme pepsin is responsible for the digestion of proteins. Pepsin, along with hydrochloric acid, is secreted by the stomach chief cells. Proteins are the most complicated molecules and must be digested further in the small intestine. The digestive juice in the stomach is made up of pepsin and hydrochloric acid.