The Energy Necessary to Drive the Bacteriorhodopsin Proton Pump That

Multiple Choice

The energy necessary to drive the bacteriorhodopsin proton pump that creates the proton gradient needed for ATP synthesis is generated by

A) a Na⁺ electrochemical gradient across the membrane.
B) a H⁺ concentration gradient across the membrane.
C) a membrane potential of 100 mV across the membrane.
D) ATP hydrolysis by ATP synthase.
E) retinal absorption of light energy.