The electron-transport chain and ATP synthase are effectively coupled. Which statement BEST describes how this occurs?
A) The electron-transport chain reoxidizes reduced cofactors.
B) The electron-transport chain generates an electrochemical gradient that provides energy for the production of ATP.
C) ATP synthase utilizes oxidized cofactors.
D) Through a series of conformational changes, ATP synthase generates ATP.

Question

Quizplus · Accepted Answer

The electron-transport chain generates an electrochemical gradient by pumping protons across the inner membrane of the mitochondria. This gradient provides energy for ATP synthase to produce ATP through a process called oxidative phosphorylation. Therefore, the electron-transport chain and ATP synthase are effectively coupled because the energy generated by the electron-transport chain is used directly by ATP synthase to produce ATP.

The Electron-Transport Chain and ATP Synthase Are Effectively Coupled