Question

The chemiosmotic coupling hypothesis of oxidative phosphorylation proposes that adenosine triphosphate (ATP) is formed because

(a) a proton gradient forms across the inner mitochondrial membrane

(b) there is a change in the permeability of the inner mitochondrial membrane towards adenosine diphosphate (ADP) 

(c) high energy bonds are formed in mitochondrial proteins 

(d) ADP is pumped out of the matrix into the intermembrane space.

Answer 1

The correct option is: (a) a proton gradient forms across the inner mitochondrial membrane

Explanation:

The chemiosmotic coupling hypothesis of oxidative phosphorylation proposed by Mitchell, explains the process of ATP formation and states that it is linked to development of a proton gradient across the mitochondrial membrane. ATP synthase, required for ATP synthesis is located in F₁ particles present in the inner mitochondrial membrane and becomes active only when there is high concentration of proton on F₀ side as compared to F₁ side. The flow of proton through F₀ channel induces F₁ particle to function as ATP synthase and the energy of proton gradient produces ATP by attaching a phosphate radical to ADP.