How does chlorophyll function in photosynthesis?

• A. It splits glucose to release energy for the cell by driving cellular respiration in mitochondria.
• B. It absorbs specific wavelengths of light and uses that energy to excite electrons, initiating the light reactions.
• C. It absorbs infrared light and converts it into heat to maintain optimal enzyme temperature in chloroplasts.
• D. It directly fixes $C_{0}2$ into carbohydrates by catalyzing the Calvin cycle.

Answer: (B)

Verified step by step guidance

1. Understand that chlorophyll is a pigment found in the chloroplasts of plant cells and is essential for capturing light energy during photosynthesis.
2. Recognize that chlorophyll absorbs specific wavelengths of light, primarily in the blue and red regions of the spectrum, and reflects green light, which is why plants appear green.
3. Know that when chlorophyll absorbs light energy, it excites electrons to a higher energy state, which is the initial step in the light-dependent reactions of photosynthesis.
4. These excited electrons are then transferred through a series of proteins in the thylakoid membrane, leading to the production of ATP and NADPH, which are energy carriers used in the Calvin cycle.
5. Note that chlorophyll itself does not split glucose, absorb infrared light for heat, or directly fix carbon dioxide; its primary role is to absorb light and initiate the light reactions by exciting electrons.