Question: 135: Identify the correct statements regarding chemiosmotic hypothesis :
(a) Splitting of the water molecule takes place on the inner side of the membrane.
(b) Protons accumulate within the lumen of the thylakoids.
(c) Primary acceptor of electron transfers the electrons to an electron carrier.
(d) NADP reductase enzyme is located on the stroma side of the membrane.
(e) Protons increase in number in stroma.
Choose the correct answer from the options given below:
(1) (a), (b) and (e)
(2) (a), (b) and (d)
(3) (b), (c) and (d)
(4) (b), (c) and (e)
Answer: Option (2)
Explanation:
The chemiosmotic hypothesis explains ATP synthesis during the light reaction of photosynthesis.
Splitting of water molecules, also called photolysis, occurs on the inner side of the thylakoid membrane facing the lumen, releasing protons into the thylakoid lumen.
Due to photolysis and electron transport, protons accumulate within the lumen of the thylakoids, creating a proton gradient across the membrane.
NADP reductase enzyme is located on the stroma side of the thylakoid membrane, where it helps in the reduction of \mathrm{NADP}^{+} to \mathrm{NADPH}.
Protons do not increase in number in the stroma; instead, they are pumped into the thylakoid lumen, decreasing proton concentration in the stroma.
Therefore, statements (a), (b), and (d) are correct according to the chemiosmotic hypothesis.