Question : Give schematic representation of cyclic photophosphorylatio

1.	Question : Give schematic representation of cyclic photophosphorylation.
Answer» Solution :(1) Cyclic photophosphorylation is a kind of photophosphorylation in which the expelled electrons return back to the reaction CENTRE following a cyclic path, in which the LIGHT energy is ABSORBED by photosynthetic pigments in light harvesting complex associated with photosystem I (PS I). (2) The light energy thus absorbed is transferred to `P_(700)` As a result of this `P_(700)` is excited and expels energy RICH electrons making it positively charged. (3) The expelled electrons are initially captured by FRS (Ferredoxin reducing substance). From which it passes the electrons to an iron containing red protein called Fd (Ferredoxin). (4) From ferredoxin, the electrons then pass through a series of electron acceptors and donors such as cytochrome-`b_(6)`, cytochrome-f and plastocyanin (Pc). (5) From plastocyanin, the de-energized electrons are transferred to `P_(700)` (6) During the transfer of electrons from ferredoxin to cytochrome-`b_(6)` and from cytochrome-`b_(6)` to cytochrome-f, the energy from electrons is released. The energy thus released is utilized for the synthesis of ATP from ADP and iP as shown under : ADP+ iP`rarr` ATP where iP is inorganic phosphate.

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