Now let's move on to step three of stage one. So it's basically not enough to add that phosphoryl group, we have to add a second phosphoryl group because remember, the entire point of step or stage one is to destabilize that glucose as much as we can. And so to further destabilize the structure of glucose to increase its energy and make it much more reactive, in step three of stage one, we have an enzyme known as phosphor fructosekinase PFK that catalyzes the addition of yet another phosphoryl group onto a carbon of that fructose. And so this we begin with fructose six phosphate and then we form fructose one six bisphosphate. And so now, instead of having one, we actually have two of these phosphate groups. And so just like this step actually requires ATP, this step also requires ATP.