help please. pH in mitochondrion

[marikas]

I am not sure about this question. can anyone help?

Suppose the pH of the intermembrane space of a mitochondrion were to FALL. Consider the fall to be immediate and temporary (i.e. not sustained) and assume that ATP synthase is fully functional and not operating at its maximum (limiting) rate. Indicate why this should have an effect on ATP synthesis as well as what the effect would be.

[plasmodesmata11]

Seeing as pH is measured by the concentration of H+, and ATP Synthase's function requires protons to move down their gradient, I'd say that increasing pH would lower the function of ATP Synthase (since it's more basic there are less protons) and the function would increase with lower pH (more protons, increased function). Hope that helps.

[marikas]

Does it mean that With the lower pH, the function of ATP synthase would increase, and protons will be driven back to the matrix, so there will be more H+ in the matrix would therefore become acidic and there would be more positive charge in the matrix than in the intermembrane space. what happens with the atp? ATP would increase then and what effect would it be. I am not sure ???

[marikas]

Does it mean that there would be more ATP produced??

[marikas]

and also then if this is just temporal and immediate then everything will go back to normal then?

[plasmodesmata11]

More ATP would not be produced. Water removes the protons on the inside when oxygen acts as the final electron acceptor. I think it would only occur faster. You're right about the other things. Afterwords it would go back to normal, I believe. Hope that helps