Question

Phosphofructokinase is a four-subunit protein with four active sites. phosphofructokinase catalyzes step 3 of glycolysis, converting fructose-6-phosphate to fructose-1,6-bisphosphate. phosphoenolpyruvate (pep) is the product of step 9 of glycolysis. the pep concentration in the cell affects phosphofructokinase activity. select the true statements about pep regulation of phosphofructokinase.

Answer 1

PEP is included in the regulation of phosphofructokinase (PFK). PFK is allosterically inhibited by PEP which means that PEP binds to PFK which results in a conformational change of PFK. As a result of this PFK is inhibited. High levels of PEP indicate a sufficient cellular energy supply and therefore there is no need for further glycolysis.