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The first acceptor of electrons from an excited chlorophyll molecule of photosystem II is
A
iron-sulphur protein
B
ferredoxin
C
quinone
D
cytochrome
Detailed Solution
In photosystem II the reaction centre chlorophyll a (P680) absorbs light of 680 nm and its electrons become excited.
The excited electrons are picked up by an electron acceptor and passed to an electron transport system.
The electron passes through pheophytin to the quinones: the bound plastoquinone QA, then QB and the mobile plastoquinone pool. Among the given choices the first acceptor is quinone.
From plastoquinone the electrons pass to the cytochrome b6-f complex, then to plastocyanin and to photosystem I.
The iron-sulphur protein and ferredoxin are electron acceptors on the reducing side of photosystem I, not photosystem II.
Cytochromes come after the quinone in the chain.
So the first acceptor of electrons from the excited chlorophyll of photosystem II is quinone.
The excited electrons are picked up by an electron acceptor and passed to an electron transport system.
The electron passes through pheophytin to the quinones: the bound plastoquinone QA, then QB and the mobile plastoquinone pool. Among the given choices the first acceptor is quinone.
From plastoquinone the electrons pass to the cytochrome b6-f complex, then to plastocyanin and to photosystem I.
The iron-sulphur protein and ferredoxin are electron acceptors on the reducing side of photosystem I, not photosystem II.
Cytochromes come after the quinone in the chain.
So the first acceptor of electrons from the excited chlorophyll of photosystem II is quinone.