The direct 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+ concentrations on opposite sides of the inner mitochondrial membrane
E. The thermodynamically favorable of phosphate from glycolysis and the citric acid cycle intermediate molecules of ADP
Answer: D