How does chlorophyll function in photosynthesis?

• A. It fixes atmospheric CO2 into sugars by catalyzing the Calvin cycle reactions.
• B. It serves primarily as a structural lipid that forms the thylakoid membrane bilayer.
• C. It absorbs photons and transfers the excitation energy to the photosystems’ reaction centers to drive electron transport.
• D. It splits water directly into O2 and electrons by acting as the oxygen-evolving enzyme.

Answer: (C)

Verified step by step guidance

1. Understand that chlorophyll is a pigment molecule found in the thylakoid membranes of chloroplasts, primarily responsible for capturing light energy during photosynthesis.
2. Recognize that chlorophyll absorbs photons (light energy) and becomes excited, meaning its electrons move to a higher energy state.
3. Learn that this excitation energy is transferred from chlorophyll molecules to the reaction centers of photosystems (Photosystem I and II), which are protein complexes involved in the light-dependent reactions.
4. Know that the reaction centers use this energy to drive electron transport chains, which ultimately lead to the production of ATP and NADPH, essential molecules for the Calvin cycle.
5. Clarify that chlorophyll itself does not fix CO2, act as a structural lipid, or directly split water; instead, its main role is to absorb light and transfer energy to initiate electron transport.