The process by which molecular nitrogen (N2) is reduced to ammonia (NH3) is called nitrogen-fixation (N2-fixation). This is the most important section of this unit and is fairly long. Here we first introduce you to the species capable of N2-fixation and describe the formation of nodules during symbiotic association.
Then we go through the reactions and-enzymes involved in the conversion of molecular nitrogen to NH3. A brief section on the genetics of N2-fixation will introduce you to the possibility of transferring, N2-fixing capability to non N2-fixers.