Plants are different from animals, since they produce the organic substances their body is made of by using some inorganic substances that can be found in the environment, such as carbon dioxide (contained in air) and water and some inorganic ions (nitrates, sulphates, and other substances contained in soil). In particular, green plants can use solar energy to turn into organic molecules the carbon contained in the atmosphere in the form of carbon dioxide. This process is called photosynthesis and is typical of autotrophic organisms.