<prompt> Which of the following enzyme does not catalyzes irreversible step in glycolysis ?HexokinasePhosphoglycerate kinasePyruvate kinasePhosphofructokinase  <response>: Ans. is b i.e., Phosphoglycorate kinase Glycolysis is regulated at 3 steps which are irreversible. These reactions are catalyzed by following key enzymes :? 1 Hexokinase and glucokinase 2 Phosphofructokinase - I 3 Pyruvate kinase. 