Now, once we form the hydroxy ethyl TPP, this same enzyme, Pyruvate dehydrogenase, also catalyzes the next step, an oxidation reduction step. Now, what basically happens is this molecule here is oxidized. So this is the oxidizing agent while this structure is reduced. So this will act as the reducing agent. And what will happen is electrons will be taken away from this acetyl group here. Or it's not actually in acetyl form just yet, but this purple region actually will abstract.