An overview of glucose metabolism

(1) Glycolysis occurs in the cytosol and results in the oxidation of glucose into two pyruvates, producing two ATP and two NADH molecules. The two pyruvates enter the mitochondrial matrix,

(2) where they are oxidized, thereby producing two acetyl groups (each attached to CoA) and two CO2 molecules. Two molecules of NADH are made in the process.

(3) The two acetyl groups then enter the citric acid cycle, where they are incorporated into organic molecules. Four CO2 molecules are then released and two ATP, six NADH, and two FADH2 are synthesized.

(4) Oxidative phosphorylation occurs along the cristae, which are formed from inner mitochondrial membrane. The NADH and FADH2 molecules that are made during these various steps are then used during oxidative phosphorylation to synthesize more ATP molecules.

The maximum yield of ATP is 34 to 38 molecules for every glucose that is completely broken down.