Figure 2. Ketogenesis and ketolysis pathways. Click for enlarged view. Fatty acid oxidation in liver mitochondria generates acetyl CoA. Under conditions of low glucose availability, the acetyl CoA cannot be oxidized via the TCA cycle because, in the liver, the oxaloacetate required for the first step (its condensation with acetyl CoA to form citrate), is unavailable being redirected to the process of glucose production (gluconeogenesis). Consequently the acetyl CoA is converted into ketone…