Glycolysis. In the third step of glycolysis, the enzyme phosphofructokinase transfers a phosphate group from ATP to fructose-6-phosphate to generate fructose-1,6-bisphosphate. In contrast, in step 10, the enzyme pyruvate kinase transfers a phosphate group from phosphoenolpyruvate to ADP to generate ATP. Using what you know about the standard free energy change associated with phosphate bonds, (briefly) explain why we observe this difference.