Final answer:
Chlorophyll in the thylakoid membrane of chloroplasts absorbs sunlight, beginning the process of photosynthesis where light energy is converted to chemical energy.
Step-by-step explanation:
Sunlight is indeed absorbed by chlorophyll in the thylakoid membrane of the chloroplasts in plant cells. This process is the beginning of photosynthesis, a crucial biological function in which plants convert light energy into chemical energy. During photosynthesis, chlorophyll captures energy from sunlight, which then initiates a series of light-dependent reactions within the thylakoids.
These reactions produce ATP and NADPH, which are vital for the subsequent Calvin cycle, taking place in the stroma of the chloroplasts. The light-dependent reactions also involve the splitting of water molecules, releasing oxygen as a byproduct. Chlorophyll is responsible for giving plants their green color, and it selectively absorbs blue and red wavelengths of light while reflecting green, which is why plants appear green to us.