Reaction 3: Phosphate Ester Synthesis
This reaction is virtually identical to reaction 1 The fructose-6-phosphate
has an alcohol group on C-1 that is reacted with phosphate from
ATP to make the phosphate ester on C-1.
Again this reaction is endothermic and thus requires energy
from a coupled reaction with ATP. ATP is used by being
hydrolyzed to ADP and phosphate giving off energy and the phosphate
for reaction with the glucose for a net loss of ATP in the overall
Hydrolysis: ATP + H2O --> ADP + P + energy
This reaction is catalyzed by phosphofructokinase.