Key Points
Key Points: Nitrogen Fixation
- Organisms called Nitrogen Fixers / Diazotrophs fix atmospheric N₂. They are of two types: Symbiotic and Free-living.
- Symbiotic Fixers — Rhizobium forms root nodules in plants of the family Fabaceae (legumes) and fixes nitrogen in association with the plant.
- Free-living Fixers — Azotobacter and Azospirillum fix nitrogen independently in the soil without forming any association.
- Energy Required — Nitrogen fixation needs 16 ATP molecules per N₂ molecule fixed. N₂ + 8H⁺ + 8e⁻ + 16ATP → 2NH₃ + H₂ + 16ADP + 16Pᵢ
Concepts [8]
- Classification of Minerals
- Functions, Mode of Absorption and Deficiency Symptoms of Macronutrients
- Functions, Mode of Absorption and Deficiency Symptoms of Micronutrients
- Deficiency Diseases and Symptoms
- Critical Concentration and Toxicity of Minerals
- Hydroponics and Aeroponics
- Nitrogen Fixation
- Special Modes of Nutrition
