Question

In photosystem I, the fist electron acceptor is:

• A. Ferredoxin
• B. Cytochrome
• C. Plastocyanin
• D. An iron sulphur protein

Answer 1

The correct option is D An iron sulphur protein

In photosystem I or photoact I electrons released by P-700 are accepted bt a substance of iron -sulphur protein complex denoted as A(FeS). A(FeS) is thus reduced and it passes these electrons to oxidized ferrodoxin (Fd) and it gets reduced. From reduced Fd, these electrons are passed to FAD which are now reduced to $FAD{H}_2$ and then electrons and hydrogen are accepted by NADP which makes $NADP{H}_2$. Here photosystem I ends.