What is the proton-motive force?
A) the force required to remove an electron from hydrogen
B) the force provided by a transmembrane hydrogen ion gradient
C) the force that moves hydrogen into the intermembrane space
D) the force that moves hydrogen into the mitochondrion
E) the force that moves hydrogen to NAD+

Question

Quizplus · Accepted Answer

The proton-motive force refers to the potential energy that is stored in a transmembrane hydrogen ion gradient, which is created by the pumping of hydrogen ions across the inner mitochondrial membrane during electron transport. This force can be used to drive ATP synthesis, as well as other energy-requiring processes in the cell. Choice A is incorrect because the removal of an electron from hydrogen refers to ionization energy, not the proton-motive force. Choice C and D are incorrect because they refer to the movement of hydrogen, rather than the force that underlies this movement. Choice E is incorrect because it refers to the destination of hydrogen rather than the force that drives its movement.

What Is the Proton-Motive Force