Glycolysis consists of ten enzyme-catalyzed steps. The pathway can be divided into two main phases: the energy investment phase and the energy payoff phase. In the energy investment phase, two ATP molecules are consumed to phosphorylate glucose and convert it into fructose-1,6-bisphosphate. In the energy payoff phase, this molecule is cleaved into two three-carbon sugars, which are further processed to produce four ATP molecules and two NADH molecules.
