Question

Chemiosmosis is a universal mechanism by which organisms harvest and store energy.

Which of the following best describes the process?

• A. It is the process of whereby a proton gradient drives an energy-requiring reaction.
• B. It is the process used to move protons up a concentration gradient for subsequent production of ATP
• C. It is the process that uses pumps to drive chemicals across the membrane.
• D. It is the movement of specific chemicals against its gradient coupled to the flow of protons down its concentration gradient.

Answer 1

Answer: (B)

It is the process used to move protons up a concentration gradient for subsequent production of ATP

Chemiosmosis is the movement of ions and protons, along and against the concentration gradient, resulting in the formation of ATP. In the initial step EMF (electron motive force) is used to drive protons into the mitochondrial matrix up its concentration gradient, and in the latter part protons are moved along the concentration gradient using ATP synthase to produce ATP.

So, the correct answer is 'It is the process used to move protons up a concentration gradient for subsequent production of ATP'