Any of a group of closely related enzymes that degrade starch, glycogen, and other polysaccharides. Plants contain both α- and β-amylases; the name diastase is given to the component of malt containing β-amylase, important in the brewing industry. Animals possess only α-amylases, found in pancreatic juice (as pancreatic amylase) and also (in humans and some other species) in saliva (as salivary amylase or ptyalin). Amylases cleave the long polysaccharide chains, producing a mixture of glucose and maltose.