Which of the following is the most likely mechanism of action of a pharmacological agent that prevents ATP generation in isolated mitochondria?
A) activation of cytochrome c
B) decrease of NADH generation by NADH dehydrogenase
C) disruption of pH gradient across mitochondrial membrane
D) increase of transport of pyruvate through the mitochondrial membrane
E) inhibition of glyceraldehydes-3-phosphate dehydrogenase

Question

Quizplus · Accepted Answer

Disruption of the pH gradient across the mitochondrial membrane would prevent ATP generation by uncoupling oxidative phosphorylation, as the proton gradient is essential for ATP synthase function.  The normal flow of electrons, through the proteins of the oxidative phosphorylation machinery, is coupled with the establishment of a proton gradient across the inner mitochondrial membrane. The establishment of this pH gradient is the chemiosmotic potential that is coupled with the production of ATP. Any disruption in this PMF, such as with the addition of an uncoupling agent like dinitrophenol, results in a loss of the energy needed for ATP synthesis but does not prevent oxygen consumption.

Which of the Following Is the Most Likely Mechanism of Action