There is reciprocal regulation of glycolytic and gluconeogenic reactions interconverting fructose-6-phosphate and fructose-1,6-bisphosphate. Which statement about this regulation is NOT correct?
A) Fructose-2,6-bisphosphate activates phosphofructokinase-1.
B) Fructose-2,6-bisphosphate inhibits fructose-1,6-bisphosphatase.
C) The fructose-1,6-bisphosphatase reaction is exergonic.
D) The phosphofructokinase-1 reaction is endergonic.
E) This regulation allows control of the direction of net metabolite flow through the pathway.

Question

Quizplus · Accepted Answer

The phosphofructokinase-1 (PFK-1) reaction, which converts fructose-6-phosphate to fructose-1,6-bisphosphate in glycolysis, is actually exergonic under cellular conditions, not endergonic as stated in option D. This means it releases energy, which contradicts the statement in D.

There Is Reciprocal Regulation of Glycolytic and Gluconeogenic Reactions Interconverting