Pepsin and its Funciont as a Gastric Gland Cell :: essays research papers

A gastric gland is a tubular structure in the vertebrate stomach that secretes gastric juices. The gastric glands have three types of cells that secrete different components of the gastric juice. One of them is being a chief cell, which is a rust color and is an inactive form of the digestive enzyme Pepsin. Pepsin begins the digestion of proteins in food. Pepsin is a Peptidases, which is an enzyme that breaks peptide bonds of proteins.   Ã‚  Ã‚  Ã‚  Ã‚  Pepsin is found in the mucosal lining of the stomach that breaks down the protein in the food we eat. A protein is an organic compound that consists of aminio acids joined by peptide bonds. Pepsin is one of three principal protein- degrading enzymes in the digestive system the other two being chymotrypsin which catalyzes the hydrolysis of peptide bonds and trypsin that acts with the other proteins to break down dietary protein molecules to their peptides and amino acids which will be absorbed by the intestinal lining. Pepsin is synthesized in an inactive form in the stomach lining; it is necessary to convert the inactive enzyme and to maintain the optimum acidity (pH 1–3) for pepsin function.   Ã‚  Ã‚  Ã‚  Ã‚  Secreting pepsin in the inactive form of pepsinogen helps to protect the cells of the gastric glands, and mucus helps protect the stomach lining from both pepsin and acid. Pepsinogen and HCl are secreted into the interior of the gastric gland. Then HCl converts pepsinogen into pepsin. Then pepsin activates more pepsinogen starting a chain reaction. Pepsin begins chemical digestion of proteins. It splits the polypeptide chains of proteins Into smaller polypeptides. Polypeptide chains are chains of amino acids linked by peptide bonds. This primes the proteins for digestion in the small intestine.