proteolytic enzyme one that catalyzes the hydrolysis of proteins and various split products of proteins, the final product being small peptides and amino acids. repressible enzyme one whose rate of production is decreased as the concentration of certain metabolites is increased.
The reaction is catalyzed by the enzyme glyceraldehyde 3-phosphate dehydrogenase. This enzyme catalyzes a multistep reaction between three substrates—glyceraldehyde 3-phosphate, the cofactor NAD +, and inorganic phosphate (P i)—and produces three products: 1,3-bisphosphoglycerate, NADH, and H +. One can think of this reaction as two reactions: (1) an oxidation/reduction reaction and (2) a condensation reaction in which an inorganic phosphate is transferred onto a molecule. β-Galactosidases (EC 184.108.40.206), also designated as lactases, are enzymes designed by nature to effect the hydrolysis of lactose (the most abundant milk sugar) to its glucose and galactose moieties. These enzymes are found in various biological systems, namely plants or microorganisms; however, yeasts, molds, and bacteria still remain the only sources for commercial purposes. It catalyzes the hydrolysis of maltose to glucose units. Mammalian intestinal mucosa secretes disaccharidases such as maltose, lactose and sucrose. Alpha-glucosidase (maltase) is used for assaying the activity of alpha amylase and for the determination of maltose in brewing. Alpha-glucosidase catalyzes the following reaction: a-GLUCOSIDASE