Phototrophs (photo=light, troph=nourishment) or photoautotrophs (photo=light, auto=self, troph=nourishment) are organisms which carry out photosynthesis. Using energy from sunlight, carbon dioxide and water are converted into organic materials to be used in cellular functions such as biosynthesis and respiration. In an ecological context, they provide nutrition for all other forms of life (besides other autotrophs such as chemotrophs).
