Practice Questions

TLS Online TPP Program

#Question id: 10132

Which of the following statements would be correct for photophosphorylation ?

#Unit 6. System Physiology – Plant

Water is oxidized and protons are released in the lumen by PSII and reduces NADP+ to NADPH in the stroma both are spontaneous processes becoz their reduction potential is positive
The sequential absorption of four photons (excitons) —known as S states, each absorption causing the loss of one electron from the Mn4Ca cluster, produces an oxidizing agent that can remove four electrons from two molecules of water, producing O2, the electrons lost from the Mn4Ca cluster pass one at a time to an oxidized Tyr residue in a PSII protein, then to P680+
An alternative path of electron is cyclic electron transfer, in which elctron move from ferredoxin back to the cytochrome b6 f complex, the cyclic pathway produces more ATP and Water produces but less NADPH produces than the noncyclic
Transfer of the two electrons to PQB reduces it to PQB 2–, and the reduced PQB 2– takes two protons from the stroma side of the medium, yielding a fully reduced plastohydroquinone (PQH2), the PQH2 then still remain bounded from the reaction center complex