Question

In the two light reactions of photosynthesis

• A. PS-1 produces a strong oxidant but PS-2 a strong reductant
• B. PS-1 produces a strong reductant like NADPH but PS-2 a strong oxidant
• C. PS-1 emits electrons for PS-2
• D. PS-1 produces ATP which is not formed by PS-2

Answer 1

Answer: (B)

PS-1 produces a strong reductant like NADPH but PS-2 a strong oxidant

PS I forms a strong reductant (for CO${}_2$ reduction) and PS II is responsible for the production of a strong oxidant (for oxidation of H${}_2$O to O${}_2$). The transfer of electrons from the weak reductant (produced by PS-II) to the weak oxidant (produced by PS-I) is coupled to ATP production.

So, the correct option is 'PS-1 produces a strong reductant like NADPH but PS-2 a strong oxidant'