Assume that the inner membrane of mitochondria would let protons pass through it easier than typically, i.e. the membrane is more permeable than usual. What effect would this have? Choose one option and explain how you arrived at your answer, and why the other options are incorrect.
a) ATP synthase (complex V) produces more ATP: If the inner membrane of mitochondria is more permeable to protons, it would lead to a decrease in the proton gradient across the membrane. This would result in ATP synthase producing less ATP, not more. Therefore, this option is incorrect.
b) The electron transport chain works less efficiently: A more permeable inner membrane would disrupt the proton gradient necessary for the electron transport chain to function efficiently. This disruption would lead to a decrease in the efficiency of the electron transport chain. Hence, this option is correct.
c) The amount of inorganic phosphate in the mitochondrial matrix increases: The permeability of the inner membrane to protons would not directly affect the amount of inorganic phosphate in the mitochondrial matrix. Therefore, this option is incorrect.
d) None of these: This option is incorrect as explained above.