Pyruvate is the end product of glycolysis in cells with mitochondria and an adequate supply of oxygen. This series of ten reactions is called aerobic glycolysis because oxygen is required to reoxidize the NADH formed during the oxidation of glyceraldehyde 3-phosphate (Figure 8.9B). Aerobic glycolysis sets the stage for the oxidative decarboxylation of pyruvate to acetyl CoA, a major fuel of the TCA (or citric acid) cycle. Alternatively, pyruvate is reduced to lactate as NADH is oxidized to NAD + (Figure 8.9C). This conversion of glucose to lactate is called anaerobic glycolysis because it can occur without the participation of oxygen. Anaerobic glycolysis allows the production of ATP in tissues that lack mitochondria (for example, red blood cells) or in cells deprived of sufficient oxygen