Briefly explain the chemiosmotic theory.

Explanation

Chemiosmotic theory was proposed by P. Mitchell.
1. ATP synthesis is linked to development of proton gradient a cross the membranes thylakoids.
2. Electrons are transported along the membrane through PS I and PS II and connected by cytochrome `b_(6)` - f complex.
3 Splitting of water molecule takes place inside of the membrane . Protons or `H^(+)` ions accumulate within the lumen of the thylakoid (1000 - 2000 times) . Protons are less in number in strong . A proton gradient is formed .
4. These protons move across the membrane because the primary acceptor of electron is located outside the membrane .
5 . The proton gradient is broken down due to the movement of proton across the membrane to the strong through `CF_(6)` of the ATP synthase enzyme .
This proton motive force created in the lumen of thylakoid or chemical stimulates ATP generation .

The evolution of one oxygen molecule (4 electrons required ) requires 8 quanta of light . `C_(3)` plants utilise 3 ATPs and 2 NADPH + `H^(+)` to evolve one Oxygen molecule . To evolve 6 molecules of Oxygen 18 ATPs and 12 NADPH `+ H^(+)` are utilised . `C_(4)` plants utilise 5 ATPs and 2 NADPH `+ H^(+)` to evolve one oxygen molecule . To evolve 6 molecules of Oxygen , 30 ATPs and 12 NADPH + `H^(+)` are utilised.