In photosynthesis, what primary role do pigments (such as chlorophylls and carotenoids) play in the light reactions?

• A. They directly synthesize ATP by pumping protons across the thylakoid membrane as the ATP synthase complex.
• B. They catalyze the fixation of $C_O$$2$ into sugars by acting as the main enzymes of the Calvin cycle.
• C. They absorb photons of specific wavelengths and transfer the captured energy to the photosystems for conversion into chemical energy.
• D. They open and close stomata to regulate gas exchange and water loss during photosynthesis.

Answer: (C)

Verified step by step guidance

1. Understand that pigments like chlorophylls and carotenoids are molecules that absorb light energy during the light reactions of photosynthesis.
2. Recognize that these pigments absorb photons of specific wavelengths, which excites their electrons to a higher energy state.
3. Know that the absorbed energy is then transferred from the pigments to the photosystems (protein complexes) embedded in the thylakoid membrane.
4. Realize that this energy transfer initiates the conversion of light energy into chemical energy by driving electron transport chains, ultimately leading to ATP and NADPH production.
5. Distinguish that pigments themselves do not directly synthesize ATP, fix carbon dioxide, or regulate stomata; their primary role is to capture and transfer light energy.