The function of chlorophyll in plants is to capture light energy, primarily from the sun, during the process of photosynthesis. Chlorophyll absorbs specific wavelengths of light, especially in the blue and red regions of the spectrum, while reflecting green light, which gives plants their characteristic color. By converting light energy into chemical energy, chlorophyll allows plants to produce glucose and oxygen from carbon dioxide and water, playing a crucial role in the energy flow within ecosystems.