Question

The calculation of the P/O ratio depends on the number of binding sites for ATP on ATP synthase and the number of which of the following? A. Protons pumped across the membrane

B. Electrons in the electron transport chain
C. NADH molecules
D. Substrates in glycolysis

Answer 1

The P/O ratio depends on the number of protons pumped across the mitochondrial membrane, which is related to the protons' contribution to the synthesis of ATP during oxidative phosphorylation.

Step-by-step explanation:

The calculation of the P/O ratio is related to the number of ATP molecules generated relative to the amount of oxygen consumed during oxidative phosphorylation in the mitochondria. Specifically, it depends on the number of protons pumped across the mitochondrial membrane during electron transport and the operation of ATP synthase. In this system, a proton motive force generated by the electron transport chain propels protons into the mitochondrial matrix through ATP synthase, which synthesizes ATP. The P/O ratio for NADH is generally 3, while for FADH2, it is 2, reflecting the different amounts of energy each of these carriers contributes to the proton gradient and thus the synthesis of ATP.