where in a eukaryotic cell does pyruvate decarboxylation occur?
In eukaryotic cells the pyruvate decarboxylation occurs inside the mitochondria, after transport of the substrate, pyruvate, from the cytosol. The transport of pyruvate into the mitochondria is via a transport protein and is active, consuming energy. Passive diffusion of pyruvate into the mitochondria is impossible because it is a polar molecule. On entry to the mitochondria the pyruvate decarboxylation occurs, producing acetyl CoA.