Question

Select the correct option:

During non-cyclic photophosphorylation, electrons are continuously lost from the reaction centre of PS II. Which source is used to replace these electrons?

• A. Sunlight
• B. $O_2$
• C. $H_{2}O$
• D. $C{O}_2$

Answer 1

Answer: (C)

$H_{2}O$

Non-cyclic photophosphorylation is the normal process of photophosphorylation in which the electron expelled by the excited photo centre does not return to it. Non-cyclic photophosphorylation is carried out in collaboration of both photosystems I and II. An electron released during photolysis of $H_{2}O$ is picked up by photo centre of PS II called $P_{680}$.The same is extruded out when the photo centre absorbs light energy (hv). Electrons released during the photolysis of water are immediately accepted by oxidised reaction centre of PS II (i.e. $P_{680}$) through an unknown substance Z.

So the correct answer is '$H_{2}O$'.