Nitrogen fixation is a process by which nitrogen in the Earth's atmosphere is converted into ammonia or other molecules available to living organisms. Nitrogen fixation is essential for all forms of life because inorganic nitrogen compounds are required for the biosynthesis of the basic building blocks of plants, animals and other life forms. Nitrogen fixation is no more than the use of di-nitrogen as the source of nitrogen atoms for growth. Bacteria, such as cyanobacteria, convert nitrogen into nitrogen gas via nitrogen fixation on the aquatic ecosystem.