The term carotene's used for several related substances having the formula C40Hx, which are synthesized by plants but can't be made by animals. Carotene's an orange photosynthetic pigment important for photosynthesis. Carotenes are responsible for the orange colour of the carrot for which it's named, and many other fruits and vegetables (for example, sweet potatoes and orange cantaloupe melon). Carotenes are also responsible for the orange colours in dry foliage. They also (in lower concentrati… (More on Carotene)