And so, again, the enzyme that catalyzes step is serene dehydrates. Now, glycine can actually be transformed into pyruvate by first transforming the glycine into serene. And the way that we form the serine from glycine is by adding a hydroxy methyl group. So where does that hydroxy methyl group come from? Well, from a molecule known as phyton methylene THF, where THF stands for tetrahydropholate. So we have glycine in the presence of water and in the presence of this molecule.