Question

A molecule enters a cell and creates pores in the inner mitochondrial membrane. Will oxidative phosphorylation continue to generate ATP?

1) Yes, because the cell membrane is still complete.
2) Yes, because ATP is required for cell function.
3) No, because there is no available oxygen.
4) No, because the proton gradient will be dissipated.

Answer 1

The creation of pores in the inner mitochondrial membrane disrupts the proton gradient essential for oxidative phosphorylation, therefore ATP cannot be generated. The correct answer is 'No, because the proton gradient will be dissipated.' The correct option is 4).

Step-by-step explanation:

When a molecule creates pores in the inner mitochondrial membrane, oxidative phosphorylation cannot continue to generate ATP efficiently. The reason is that the creation of pores in the inner mitochondrial membrane undermines the essential proton gradient required for the generation of ATP.

In oxidative phosphorylation, for ATP to be synthesized, protons (H+) must flow through ATP synthase, a protein embedded in the inner mitochondrial membrane that functions similarly to a turbine.

This proton flow is driven by an electrochemical gradient that is disrupted if there are pores causing protons to leak back into the mitochondrial matrix, effectively 'short-circuiting' the system.

The correct answer to the student's question is option 4) No, because the proton gradient will be dissipated. This proton gradient is the result of an electron transport chain that pumps protons into the intermembrane space, creating a high concentration of H+ ions relative to the mitochondrial matrix.

It is the flow of these protons back into the matrix through ATP synthase that drives the synthesis of ATP from ADP and inorganic phosphate (Pi).