Question

Assertion (A): Decrease in the proton number in stroma and accumulation of more protons in the lumen creates proton gradient across the membrane.
Reason (R): Energy is released by the breakdown of proton gradient by ATPase and helps in synthesis of ATP.
Identify the correct option from the following:

• A. Both (A) and (R) are true, and (R) is correct explanation of (A)
• B. Both (A) and (R) are true, but (R) is not the correct explanation of (A)
• C. (A) is true, but (R) is false
• D. (A) is false, but (R) is true

Hint:

In assertion-reason questions, check both statements independently first, then verify if the reason logically explains the assertion.

Answer 1

The Correct Option is A

During photophosphorylation in chloroplasts, a proton gradient is created by moving protons into the thylakoid lumen, decreasing their concentration in the stroma. The energy from this proton gradient is utilized by ATP synthase (ATPase) to produce ATP. Thus, both the assertion and reason are correct, and the reason explains the assertion.