Figure 1.

Simplified scheme of the mitochondrion with TCA cycle and the intersecting anaplerotic and cataplerotic reactions, OXPHOS complexes I–IV, and ATP synthase (complex V). In the mitochondrial matrix the PDC catalyzes the irreversible conversion of pyruvate, NAD+ and CoA into acetyl-CoA, NADH and CO₂. PDK inactivate the PDC by phosphorylating its E1α subunit, which hinders the entrance of acetyl-CoA into the TCA cycle. The PDC is reactivated upon dephosphorylation by PDP. Adapted from (5). Inspiration (4, 6).