Any of a group of yellow, orange, red, or brown pigments chemically related to terpenes. Carotenoids are responsible for the characteristic colour of many plant organs, such as ripe tomatoes, carrots, and autumn leaves. They also occur in certain algae and other photosynthesizing organisms (such as phototrophic bacteria), in which they function as accessory pigments in the light-dependent reaction of photosynthesis (see photosynthetic pigments). See carotene; xanthophyll.
Subjects: Biological Sciences.