Question

Which of the following statements must be true in order for mitochondrial ATP synthase to function properly?

1) The pH of the intermembrane space must be higher than the pH of the mitochondrial matrix.
2) There must be no difference in pH between the mitochondrial matrix and the intermembrane space.
3) The pH of the intermembrane space must be lower than the pH of the mitochondrial matrix.

Answer 1

Answer;

The pH of the intermembrane space must be lower than the pH of the mitochondrial matrix.

Step-by-step explanation;

• During chemiosmosis 10 protons are shuffled from the matrix to intermembrane space. This generates a pH gradient across the inner mitochondrial membrane, with the pH higher in the matrix than in the cytosol, where the pH is generally close to 7.
• The pH of the intermembrane space is lower than the pH of the mitochondrial matrix. The electrochemical proton gradient across the inner mitochondrial membrane is used to drive ATP synthesis in the critical process of oxidative phosphorylation.