Question

The proton motive force (pmf) is driven by __________. the proton motive force (pmf) is driven by __________. the pumping of protons through the plasma membrane the pumping of electrons though the plasma membrane the difference in charge across the plasma membrane with protons outside the membrane the difference in charge across the plasma membrane with electrons outside the membrane

Answer 1

 When a cell membrane becomes energized due to electron transport reactions by the electron carriers embedded in it then this results in proton motive force (PMF). This way the cell becomes a tiny battery. 
The proton motive force (PMF) is driven by the difference in charge across the plasma membrane with protons outside the membrane.