Amylase is an enzyme that hydrolyses the alpha bonds of large, alpha-linked polysaccharides, such as starch and glycogen. The catalyzed products are glucose and maltose. In the human body, both salivary and pancreatic amylase is produced. Amylose is a polysaccharide composed of D-glucose units and is one of the two components of starch. Amylase acts on the covalent bonds that join these glucose units together and ultimately cleaves them apart.
According to the Research Collaboratory for Structural Bioinformatics' Protein Data Bank, one of the major jobs of digestive enzymes is to break long-chain polysaccharides into individual glucose units, which are then delivered by the blood to hungry cells throughout the body. Salivary amylase, or ptyalin, is secreted by the salivary glands and is found in the mouth. It breaks down large, insoluble starches into soluble forms, including amylodextrin, erythrodextrin and achrodextrin. Once in the stomach, salivary amylase is inactivated by gastric acid. Pancreatic amylase is found within the pancreatic juices secreted by the pancreas. Pancreatic juices drain into the duodenum of the small intestine via the pancreatic duct, specifically the ampula of Vater. The pancreatic amylase enzymes cleave the glycosidic bonds within amylose, resulting in maltose, maltotriose and dextrin. Maltose is a disaccharide formed from two glucose molecules. The enzyme maltase acts on maltose to yield two glucose molecules. Maltotriose is a trisaccharide formed from three glucose molecules and is acted upon by a glucanotransferase enzyme. Individual glucose molecules are the human body’s primary energy source. Dextrin acts as a water-soluble dietary fiber, aiding in digestion.