Now, remember the fate of pyruvate is based on the availability of oxygen. When oxygen is available, we undergo aerobic respiration. In the presence of oxygen, pyruvate is transported from the cytosol to the mitochondrial matrix. Here, pyruvate is oxidized by pyruvate dehydrogenase to Acetyl CoA. Remember, when it comes to our oxidation reactions, the class of enzymes that we utilize are the dehydrogenases. That's why it's called pyruvate dehydrogenase. It's the substrate name followed by dehydrogenase. In this process, one NAD+ is reduced to one NADH. We're going to say here that one carbon is lost as carbon dioxide.
If we take a look at our reaction, we have our pyruvate molecule here. We've highlighted the carboxyl group of this pyruvate molecule. We have coenzyme A with its thiol group, and we have NAD+. Here, we would lose carbon dioxide and have the generation of NADH. This would be helped by enzyme pyruvate dehydrogenase. In this process, we oxidize to become our Acetyl CoA molecule. So just remember, this happens under aerobic respiration, which can only occur when there's oxygen available.