What is Nitrogen Fixation?
Answers
Nitrogen fixation is a process by which molecular nitrogen in the air is converted into ammonia (NH. 3) or related nitrogenous compounds in soil. Atmospheric nitrogen is molecular dinitrogen, a relatively nonreactive molecule that is metabolically useless to all but a few microorganisms. Bacteria like Rhizobium helps in this process.
Nitrogen fixation is a process by which molecular nitrogen in the air is converted into ammonia (NH
3) or related nitrogenous compounds in soil.[1] Atmospheric nitrogen is molecular dinitrogen, a relatively nonreactive molecule that is metabolically useless to all but a few microorganisms. Biological nitrogen fixation converts N
2 into ammonia, which is metabolized by most organisms.
Nitrogen fixation is essential to life because fixed inorganic nitrogen compounds are required for the biosynthesis of all nitrogen-containing organic compounds, such as amino acids and proteins, nucleoside triphosphates and nucleic acids. As part of the nitrogen cycle, it is essential for agriculture and the manufacture of fertilizer. It is also, indirectly, relevant to the manufacture of all nitrogen chemical compounds, which includes some explosives, pharmaceuticals, and dyes.
Nitrogen fixation is carried out naturally in soil by microorganisms termed diazotrophs that include bacteria such as Azotobacter and archaea. Some nitrogen-fixing bacteria have symbiotic relationships with plant groups, especially legumes.[2] Looser non-symbiotic relationships between diazotrophs and plants are often referred to as associative, as seen in nitrogen fixation on rice roots. Nitrogen fixation occurs between some termites and fungi.[3] It occurs naturally in the air by means of NOx production by lightning.[4][5]
All biological nitrogen fixation is effected by enzymes called nitrogenases.[6] These enzymes contain iron, often with a second metal, usually molybdenum but sometimes vanadium.