We have the pyruvate and the TPP, and this is actually attached onto the enzyme, the pyruvate dehydrogenase. And what happens is this entire component here is essentially removed. In addition, we have to input two H plus ions. Why? Well, because one of them is used to basically form a hydroxyl group, and the other one is attached onto this carbon here. And so once the bond forms between this carbon of the TPP and this carbon here, this is what we form.