The direct most immediate energy source that drives ATP synt

The direct (most immediate) energy source that drives ATP synthesis during respiratory oxidative phosphorylation is:

a) oxidation of glucose to CO2 and water.

b) the thermodynamically favorable flow of electrons from NADH to the mitochondrial electron transport carriers.

c) the final transfer of electrons to oxygen.

d) the difference in H+ concentration on opposite sides of the inner mitochondrial membrane.

e) the thermodynamically favorable transfer of phosphate from glycolysis and the citric acid cycle intermediate molecules of ADP.

Solution

D ) the difference in H+ concentration on opposite sides of the inner mitochondrial membrane.

There is a flow of electrons through complexes I, III and IV that results in pumping of protons across the inner mitochondrial membrane, which makes the matrix alkaline relative to the intermembrane space. This proton motive force , provides energy for ATP synthesis from ADP and Pi by FoF1 complex in the inner membrane.