Question

Select the correct option:

In cyclic photophosphorylation, the electron released by reaction centre ($P_{700}$) is ultimately accepted by

• A. ferredoxin
• B. $NAD{P}^{+}$
• C. reaction centre ($P_{700}$)
• D. plastocyanin

Answer 1

The correct option is C reaction centre ($P_{700}$)

In cyclic photophosphorylation, an electron expelled by the excited photocentre ($P_{700}$) is returned to it after passing through a series of electron carriers. Its photocentre $P_{700}$ extrudes an electron with a gain of 23 kcal/mole of energy after absorbing a photon of light (hv). After losing the electron the photocentre becomes oxidised. The expelled electron passses through a series of carriers including X or $A_0$ (a special $P_{700}$hlorophyll molecule),$A_1$ (a quinone),FeS complexes $(Fe{S}_X,Fe{S}_A,Fe{S}_B)$, ferredoxin (Fd), Plasticine(PQ), cytochrome b-f complex and plastocyanin (PC) before returning to photocentre.

So the correct answer is 'reaction centre ($P_{700}$)'.