Allosteric control, PFK-1 regulation, and energy sensing
Glycolysis is regulated primarily at phosphofructokinase-1 (PFK-1), the committed step converting fructose-6-phosphate to fructose-1,6-bisphosphate. PFK-1 is allosterically inhibited by high ATP and citrate (signaling sufficient energy), and activated by AMP, ADP, and fructose-2,6-bisphosphate (F2,6BP), the most potent activator. Hexokinase provides a second control point via product inhibition by glucose-6-phosphate, while pyruvate kinase is allosterically activated by its substrate fructose-1,6-bisphosphate (feedforward activation).