Question

Would there be an electrical potential across the inner membrane of the mitochondria when chemiosmosis is active? Why or why not? If so, which compartment in the mitochondria would have a more positive charge?

Answer 1

Yes, there is an electrical potential across the inner membrane of the mitochondria during chemiodmosis.

The energy released from electron transport chain is used to pump the proton across inner mitochondrial membrane from mitochondrial matrix to intermembranous space. Thus the concentration of hydrogen ion (proton) becomes very higher in the intermembranous space. Since, the hydrogen ion has positive charge the electrical potential of mitochondrial matrix become -170 mv.

During chemiosmosis the hydrogen ion from intermembranous space diffuses down to the electrochemical gradients with the help of an enzyme ATP synthase which synthesizes ATP.

Hence, during chemiosmosis the intermembranous space will have more positive charges.