Nitrogen Fixation
Definition
Nitrogen fixation is the conversion of atmospheric nitrogen (N₂) into ammonia (NH₃) or other usable nitrogen compounds. This can occur biologically (by bacteria like Rhizobium) or abiotically (lightning, industrial processes). It is essential for making nitrogen available to plants.
Key Points for NEET
- 1Converts N₂ to NH₃ (ammonia)
- 2Biological fixation by Rhizobium, Azotobacter, cyanobacteria
- 3Rhizobium forms symbiosis with legume roots
- 4Nitrogenase enzyme requires anaerobic conditions
- 5Industrial fixation: Haber-Bosch process
Example
Rhizobium bacteria in root nodules of pea plants fixing atmospheric nitrogen
Asked in NEET
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