If we somehow replace the phosphoryl group here with an H atom, then it will be able to transform spontaneously into the more stable ketone form. In fact, that's exactly what will happen in this reaction. So this reaction takes place because this molecule has a very high phosphoryl transfer potential, even higher than ATP. And so in the presence of ADP, this phosphoryl group will be transferred onto that ADP. And in the presence of an H plus ion, this will bind onto this oxygen. And so we form this Pyruvate molecule in the enol form as well as an ATP.