Trypsin is an enzyme that digests proteins (i.e. a protease). It is secreted in an inactive form (trypsinogen) by the pancreas into the duodenum. There, trypsinogen is acted on by an enzyme (enterokinase) produced in the duodenum to yield trypsin. The active enzyme plays an important role in the digestion of proteins, breaking down peptide bonds in the amino acids lysine and arginine, in the anterior portion of the small intestine. It also activates other proteases in the pancreatic juice.
Chymotrypsin is an enzyme produced in the body that aids in the digestion of food by breaking down proteins. It is made in the small intestine, by complex chemical reactions, from chymotrysinogen. This, together with other digestive substances, is secreted by the pancreas through the pancreatic duct into the duodenum, which lies between the stomach and the small intestine. The secretion is controlled partly by the vagus nerve and partly by hormones, which are released automatically when food enters the duodenum.