Final answer:
The statement regarding the proton-motive force as the driving force that pulls protons into the mitochondrial matrix, comprising both a pH gradient and a voltage gradient, is true.
Step-by-step explanation:
The student's statement that the driving force pulling protons into the mitochondrial matrix is called the proton-motive force is true. The proton-motive force is indeed a combination of two forces: a large force due to the pH gradient and a smaller force from the voltage gradient across the inner mitochondrial membrane. This force is essential in the process of oxidative phosphorylation, where the energy stored in the proton gradient is used to make ATP, the cell's currency of energy. The gradient is established by the pumping of hydrogen ions (protons) through the electron transport chain and across the inner mitochondrial membrane, creating an electrochemical gradient that consists of both a difference in charge and a difference in pH between the mitochondrial matrix and the intermembrane space.