But it's not actually this simple because we also have an important molecule involved that is present in catalytic amounts in a very small amount. And this molecule is two or three bisphosphoglycerate or two three BPG. Now, this is the same exact molecule that we discussed when we mentioned hemoglobin's ability to bind oxygen. So in that discussion, we mentioned that two, three BPG is actually an intermediate in the process of glycolysis. And two, three BPG can basically affect the affinity of hemoglobin for oxygen. Now, what exactly is the function of two three BPG in this reaction?