Nitrogen is an essential component of amino acids and nucleic acids, which are the building blocks of all living things. Nitrogen makes up most of the atmosphere, but the N2 in the atmosphere cannot be used by most organisms. Nitrogen fixation is the process by which atmospheric nitrogen is transformed into forms that are more usable in biological processes. Although life needs nitrogen, only a few organisms are actually able to fix nitrogen out of the atmosphere. The biochemical reactions of the few types of bacteria that contribute to the recycling of nitrogen may be discussed. All other life is dependent on these organisms for the continuation of the essential nitrogen cycle. …