3.2 The place of glycolysis in glucose degradation

Figure 3.2-1 gives an overview of the steps involved in the complete degradation of glucose. In this process, glycolysis is only the first step. The pyruvate it generates is turned into acetyl-CoA by pyruvate dehydrogenase. Acetyl-CoA is completely degraded in the citric acid cycle and the respiratory chain. While some ATP is generated at each of these stages, most of it is produced in the respiratory chain.

If glucose is available in excess of metabolic demands and of the capacity of glycogen synthesis, it will yet be broken down by glycolysis and pyruvate dehydrogenase to acetyl-CoA. However, acetyl-CoA will then be fed into fatty acid synthesis, which occurs in the liver and the fat tissue.