Which of the following events occurs last?
A)Hydrogen ions diffuse into inner mitochondrial compartment.
B)Hydrogen ions are moved from inner to outer mitochondrial compartment.
C)The movement of hydrogen ions through special channels is coupled to ATP production.
D)A hydrogen ion concentration gradient is established.
E)NADH transfer electrons to the electron-transport chain.

Question

Quizplus · Accepted Answer

The movement of hydrogen ions through special channels being coupled to ATP production occurs last in the process of oxidative phosphorylation in the mitochondria. This is because the electron transport chain results in the creation of a hydrogen ion concentration gradient across the inner mitochondrial membrane, which is then used by ATP synthase to produce ATP through the process of chemiosmosis. The other events listed (NADH transferring electrons, establishment of a hydrogen ion gradient, diffusion of hydrogen ions into the inner compartment, and movement of hydrogen ions from inner to outer compartment) all occur before the hydrogen ion movement through ATP synthase, and are part of the process of establishing the hydrogen ion gradient.

Which of the Following Events Occurs Last