Chlorophyll is any of several related green pigments found in cyanobacteria and in the chloroplasts of algae and plants.[2] Its name is derived from the Greek words χλωρός (khloros, "pale green") and φύλλον (phyllon, "leaf").[3] Chlorophyll allows plants to absorb energy from light.
Chlorophylls absorb light most strongly in the blue portion of the electromagnetic spectrum as well as the red portion.[4] Conversely, it is a poor absorber of green and near-green portions of the spectrum. Hence chlorophyll-containing tissues appear green because green light, diffusively reflected by structures like cell walls, is less absorbed.[1] Two types of chlorophyll exist in the photosystems of green plants: chlorophyll a and b.[5]