Protein digestion
Meat is a protein source.
Meat is a natural form of protein. Protein digestion starts in the stomach with the enzyme pepsin. Pepsin catalysis the hydrolysis of peptide bonds to reduce large proteins to intermediate sized polypeptides. Digestion of proteins continues in the small intestine with enzymes(trypsin and chymotrypsin) from the pancreas that reduce polypeptides into dipeptides. Further hydrolysis by carboxypeptidase (from the pancreas) produces free amino acids.
Amino acids absorbed through the intestinal wall are used as building blocks to manufacture new proteins that the body needs. Any amino acid that is not needed for protein synthesis is converted into urea (pictured on the right) and dissolved in the urine. Proteins are not stored in the body, they are used immediately or removed from the body through the urine.
Urea molecule is the form in which nitrogen from aminoacids is removed from the body