What Effect Will Increasing the Number of C Subunits in ATP

Question

What effect will increasing the number of c subunits in ATP synthase have on the P:O ratio?
A) It will increase for both NADH and FADH2.
B) It will increase for NADH and decrease for FADH2.
C) It will decrease for NADH and increase for FADH2.
D) It will decrease for both NADH and FADH2.
E) It will remain unchanged for both NADH and FADH2.

Accepted Answer

The P:O ratio, which indicates the number of ATP molecules synthesized per oxygen atom reduced, is influenced by the efficiency of ATP synthase. Increasing the number of c subunits in ATP synthase makes the enzyme less efficient, as more protons are required to make one rotation and synthesize ATP. This inefficiency leads to a decrease in the P:O ratio for both NADH and FADH2, as more protons (and thus more electron transport) are needed per ATP synthesized.