Which of the following is correctly matched with the photosystem in which it primarily functions during the light-dependent reactions of photosynthesis?

• A. P700 chlorophyll — Photosystem II
• B. Oxygen-evolving complex — Photosystem I
• C. P680 chlorophyll — Photosystem II
• D. Plastocyanin — Photosystem II

Answer: (C)

Verified step by step guidance

1. Understand the light-dependent reactions of photosynthesis: These reactions occur in the thylakoid membranes of chloroplasts and involve two photosystems, Photosystem I (PSI) and Photosystem II (PSII), which work together to convert light energy into chemical energy.
2. Recall the key components of each photosystem: Photosystem II (PSII) contains the P680 chlorophyll molecule, which absorbs light at a wavelength of 680 nm. Photosystem I (PSI) contains the P700 chlorophyll molecule, which absorbs light at a wavelength of 700 nm.
3. Analyze the oxygen-evolving complex: This complex is associated with Photosystem II (PSII) and is responsible for splitting water molecules (H₂O) into oxygen (O₂), protons (H⁺), and electrons. It is not part of Photosystem I (PSI).
4. Understand the role of plastocyanin: Plastocyanin is a mobile electron carrier that transfers electrons from the cytochrome b6f complex to Photosystem I (PSI). It is not directly associated with Photosystem II (PSII).
5. Match the correct components to their respective photosystems: P680 chlorophyll is correctly matched with Photosystem II (PSII), as it is the primary chlorophyll molecule in this photosystem. The other options are incorrectly matched based on their roles in the light-dependent reactions.