And in the second step, this is when we actually produce that ethanol. So in the first step, we have the decarboxylation reaction catalyzed by pyruvate decarboxylase the coenzyme Thiamine pyrophosphate, which is a Thiamine derivative. So Thiamine vitamin is the vitamin B one. It assists in this process which transforms the pyruvate into acetal aldehyde as well as releasing this CO2 molecule shown here. Now, what about step two? Well, in step two we have a different enzyme and this enzyme is known as alcohol dehydrogenase.