α-amylase, a metallo-enzyme, attacks the starch molecule by randomly hydrolyzing
any of the α-1,4 linkages. This endo-enzyme is present in a number of isozyme forms in
germinating barley. Several isozymes are recognized, including α-amylases I and II, each
shown to be products from two separate gene families. α-Amylase only appears during
germination following its de novo synthesis triggered by gibberellic acid