Question

The correct sequence of flow of electrons in the light reaction is

• A. PSI, plastoquinone, cytochromes, PSII, ferredoxin
• B. PSI,plastoquinone, cytochromes, PSII, ferredoxin
• C. PSI, ferredoxin,PSII,
• D. PSII, plastoquinone, cytochromes, PSI, ferredoxin

Answer 1

The correct option is D PSII, plastoquinone, cytochromes, PSI, ferredoxin

The correct sequence of flow of electrons in the light reaction

• Initially, the light of 680 nm wavelength falls on P680 (PSII), and the electron in chlorophyll a present in the reaction center, gets excited
• The excited electron is then passed to electron carriers such as Pheophytin followed by plastoquinone (PQ), $Cyt{b}_{6}f$ and then to plastocyanin (PC).
• PC then excites electrons in chlorophyll a presents in the reaction center of P700 (PSI).
• Similarly, the excited electron is transferred to electron carriers and finally to ferredoxin (Fd).

Thus, the correct sequence of flow of electrons is:
PS-II →plastoquinone → cytochromes → PSI → ferredoxin

Final answer: PSII, plastoquinone, cytochromes, PSI, ferredoxin.