 In glycolysis , glucose and glycerol are metabolized to pyruvate via the glycolytic pathway . In most organisms , this process occurs in the cytosol , but , in some protozoa such as the kinetoplastids , this is carried out in a specialized organelle called the <unk> . Glycolysis generates a net two molecules of ATP through substrate phosphorylation catalyzed by two enzymes : <unk> and pyruvate kinase . Two molecules of NADH are also produced , which can be oxidized via the electron transport chain and result in the generation of additional ATP by ATP synthase . The pyruvate generated as an end @-@ product of glycolysis is a substrate for the Krebs Cycle . 
