Chlorophyll

The term photosynthesis is derived from ancient Greek. The first part of the name φῶς phōs means "light" in English refers to the fact that light is the driving force for photosynthesis. The word σύνθεσις sýnthesis means "composition" and refers to the conversion of molecules to other molecules In phototrophic organisms, light energy is captured by special, light-absorbing dyes (chromophores). In the cell, however, these chromophores always occur bound to special proteins, since otherwise undesirable chemical reactions can occur. This complex of chromophore and protein is also called pigment.

The best known photosynthetic pigment is chlorophyll ("leaf green"). This is where the chemical photosynthesis reaction takes place.