What establishes the electrochemical gradient across a membrane to provide energy for ATP production?

Question

Quizplus · Accepted Answer

Hydrogen ions are pumped across the membrane by carrier proteins of the electron transport chain to establish an electrochemical gradient. This gradient includes both a chemical component (difference in concentration of H+ ions) and an electrical component (difference in charge across the membrane). This gradient is necessary for ATP synthase to produce ATP by allowing H+ ions to flow back into the organelle and provide energy for the reaction. The chloroplast's electron transport system also contributes to establishing the gradient, but it is the pumping of hydrogen ions by carrier proteins that is essential. Choice D is incorrect as it includes an incorrect statement about hydrogen ions collecting on the outside of the organelle membrane.

What Establishes the Electrochemical Gradient Across a Membrane to Provide