Which green pigment found in chloroplasts absorbs light energy to drive the synthesis of organic compounds?

• A. Anthocyanin
• B. Chlorophyll
• C. Xanthophyll
• D. Carotene

Answer: (B)

Chlorophyll is the green pigment in chloroplasts that captures light energy to power photosynthesis. It absorbs mainly red and blue light and reflects green, which is why plants look green. When chlorophyll absorbs light, its electrons become excited and drive the light-dependent reactions, producing ATP and NADPH. Those energy-rich molecules then fuel the Calvin cycle, where carbon dioxide is fixed into organic molecules such as glucose.

Other pigments present in the chloroplast, like carotene and xanthophyll, are accessory pigments that broaden the range of light absorbed and help protect the photosynthetic machinery, but they don’t directly drive the synthesis of organic compounds. Anthocyanin is not a chloroplast pigment involved in photosynthesis. So the pigment that directly drives synthesis in chloroplasts is chlorophyll.