Which statement is not correct about photosystems I and II.

The correct answer is PSI produces a strong oxidant, capable of reducing NADP^*

Concept:

• Photosystems I (PSI) and II (PSII) are essential components of the light-dependent reactions in photosynthesis, which occur in the thylakoid membranes of chloroplasts.
• PSI and PSII work together to convert light energy into chemical energy, facilitating the production of ATP and NADPH.
• Each photosystem has its own specific role and absorption characteristics, contributing to the overall efficiency of photosynthesis.

Explanation:

• PSI absorbs far-red light of wavelengths greater than 680 nm: This statement is correct. Photosystem I primarily absorbs light at a wavelength of 700 nm (P700), which is in the far-red spectrum.
• PSI produces a strong oxidant, capable of reducing NADP^*: This statement is incorrect. PSI produces a strong reductant, not an oxidant. The primary role of PSI is to transfer electrons to NADP⁺ to form NADPH.
• PSII absorbs red light of 680 nm: This statement is correct. Photosystem II primarily absorbs light at a wavelength of 680 nm (P680), which is in the red spectrum.
• PSII produces a very strong oxidant, capable of oxidizing water: This statement is correct. PSII produces a strong oxidant, P680^*, which is capable of oxidizing water molecules to release oxygen, protons, and electrons.

Conclusion:

In summary, the correct answer is that PSI does not produce a strong oxidant capable of reducing NADP^*. Instead, PSI produces a strong reductant that reduces NADP⁺ to NADPH. The other statements accurately describe the absorption characteristics and functions of PSI and PSII in the photosynthetic process.