What role does chlorophyll play in photosynthesis?

• A. It absorbs light energy (especially red and blue wavelengths) to excite electrons that initiate the light-dependent reactions.
• B. It splits water molecules to release O2 by acting as the oxygen-evolving enzyme.
• C. It serves as the final electron acceptor in the electron transport chain to form NADPH.
• D. It fixes atmospheric CO2 into carbohydrates by directly catalyzing the Calvin cycle.

Answer: (A)

Verified step by step guidance

1. Understand that chlorophyll is a pigment molecule found in the chloroplasts of plant cells, primarily responsible for capturing light energy during photosynthesis.
2. Recognize that chlorophyll absorbs specific wavelengths of light, mainly red and blue, which excites its electrons to a higher energy state.
3. Know that these excited electrons are then transferred through a series of proteins in the thylakoid membrane, initiating the light-dependent reactions of photosynthesis.
4. Clarify that chlorophyll itself does not split water molecules; instead, the oxygen-evolving complex associated with Photosystem II performs this function to release O2.
5. Understand that chlorophyll is not the final electron acceptor nor does it directly fix CO2; these roles are carried out by other molecules and enzymes in the photosynthetic process.