What establishes an electrochemical gradient across a membrane to provide energy for ATP production?
A) The mitochondrion's electron transport system provides the ions
B) Hydrogen ions naturally collect on the outside of the organelle membrane
C) Hydrogen ions are pumped across the membrane by carrier proteins
D) All of the above establish the electrochemical gradient

Question

Quizplus · Accepted Answer

Hydrogen ions are pumped across the membrane by carrier proteins, establishing an electrochemical gradient. This gradient provides the necessary energy for ATP production. The mitochondrion's electron transport system contributes to the gradient by shuttling electrons which are used in the pumping process, but it does not directly provide the ions. Hydrogen ions do not naturally collect on one side of the membrane without the presence of carrier proteins to actively transport them. Therefore, the correct answer is C.

What Establishes an Electrochemical Gradient Across a Membrane to Provide