Converts light energy into chemical energy and stores it as static energy in the sugary food produced. This energy is subsequently used by carnivorous plants or to help in the secondary nutrition of herbivores. Apart from green plants, this process is also observed in some germs and some protozoa. In the process of physiological oxidation , in the presence of sunlight in living organisms (plants) containing some germs , protozoa and chlorophyll, simple sugars are produced by the chemical reaction of water absorbed from the environment by carbon dioxide and root hairs.