Question

Chemiosmotic theory of ATP synthesis in the chloroplast and mitochondria is based on:

• A. Proton gradient
• B. Accumulation of $K^{+}$ ions
• C. Accumulation of $N{a}^{+}$ions
• D. Membrane permeability

Answer 1

The correct option is A Proton gradient

According to the chemiosmosis theory of ATP generation, the ATP is generated utilizing the electrochemical gradient generated due to the accumulation of protons in the thylakoid lumen of chloroplast or peri-mitochondrial space in mitochondria.

The accumulation of protons gives rise to an electric gradient, due to the accumulation of positive charge and a chemical gradient due to the accumulation of hydrogen atom.

When protons move along this electrochemical gradient through $F_0-F_1$ ATP synthase enzyme complex, ATP generation occurs.

Thus, the correct answer is "proton gradient".