Question

Assertion: Protons or hydrogen ions produced by photolysis of water accumulate in the lumen of thylakoids.
Reason: Photolysis of water takes place in the inner membrane of thylakoids.

• A. Both, assertion and the reason are true and the reason is the correct explanation of the assertion.
• B. Both, assertion and the reason are true but the reason is not the correct explanation of the assertion.
• C. The assertion is true but the reason is false.
• D. Both, the assertion and the reason are false.

Answer 1

The correct option is B

Both, assertion and the reason are true but the reason is not the correct explanation of the assertion.

The first step in the photosynthesis is the light-driven oxidation (splitting or photolysis) of water. It provides electrons for the photosynthetic electron transport chains as well as protons for the establishment of a proton gradient. It occurs on the lumenal side of the thylakoid membrane. During photolysis, water is oxidised to oxygen, protons and electrons. Protons accumulate in the lumen.