Which pigment is primarily responsible for absorbing light energy in plants to drive photosynthesis?

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

Answer: (A)

Light energy capture for photosynthesis relies primarily on chlorophyll. This pigment sits in the photosystems of the chloroplasts and has a strong ability to absorb blue and red light. When chlorophyll absorbs photons, its electrons reach an excited state and transfer energy to the photosynthetic electron transport chain, driving the production of ATP and NADPH needed to convert CO2 into sugars. Other pigments like carotenoids and xanthophylls broaden the spectrum of light that can be used and help protect the plant from light-caused damage, but they act as assistants by transferring energy to chlorophyll rather than serving as the main energy absorbers. Chlorocatechin isn’t a standard pigment involved in photosynthesis. So chlorophyll is the primary pigment responsible for absorbing light energy to drive photosynthesis.