Figure 1: Glucose metabolism at the normal and hypoxic conditions. (a) Glucose is metabolized to pyruvate; the latter undergoes Crebb’s cycle in mitochondria and catabolized to CO2 and oxygen, while 38 molecules of ATP are synthesized. (b) Anaerobic metabolism of glucose, resulting in lactate production and two molecules of ATP. No mitochondria are involved in this process. Cancerous cells use this way of glucose metabolism even at the normal conditions, that is, so-called “aerobic” glycolysis takes place.