And if we sum up these two reactions, we see that everything will cancel except these two molecules. And so, by summing up these two steps, we get back this net reaction. So we see that in the first step, a phosphoryl group is transferred from that modified histidine on that enzyme onto the three phosphorglycerate. So at the second carbon position to form the two, three BPG. And that two, three BPG doesn't exist for a very long period of time because it's not very stable. It has too much charge in close proximity.