Question

Weight loss can occur when glucose is oxidized to CO2 rather than being stored as glycogen. The first step in glucose oxidation is glycolysis. A 1930s diet drug, DNP, made the inner mitochondrial membrane permeable to protons, increasing the rate of glycolysis. What is the explanation for the DNP-induced increase in glycolysis

A. High ATP activates phosphofructokinase.
B. High AMP inhibits phosphofructokinase.
C. High ADP activates phosphofructokinase.
D. DNP also makes the inner mitochondrial membrane leaky to glucose, increasing the ability of the mitochondria to perform glycolysis.

Answer 1

Increasing permeability of the inner mitochondrion membrane to protons uncouples proton transport with ATP synthesis. As ATP synthesis in oxidative phosphorylation across ATP synthase is dependent on the proton gradient, increasing permeability of the membrane would reduce the amount of ATP synthesized as less protons will flow through ATP synthase. ADP is thus not converted to ATP and there is high amounts of ADP and AMP. High amounts of ADP and AMP will activate the glycolytic pathways and hence actively PFK hence the answer would be C.