And remember, the enol form of this molecule contains a hydroxyl group here and a double bond between this carbon and this carbon. So remember from organic chemistry that whenever we have an aldol condensation reaction, we essentially have an enorm intermediate molecule. And so, to essentially stimulate the formation of this enormous molecule that will act as a nucleophile that will help form the citrull coenzyme A, we see that these enzymes, or I should say these catalytic residues of the enzyme, actually help with this process. So HistoGene 274 uses the hydrogen ion attached onto this nitrogen. It donates that H ion onto the oxygen of this carbonyl group shown here. And what that does is it weakens this double bond between the carbon and the oxygen at the same time as pertain 375 basically acts as a base and it takes away the H ion from the methyl group shown here.