MIC 201 Lecture Notes - Lecture 11: Nitrogen Fixation, Anaerobic Respiration, Nitrification
10 Apr 2019
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Document Summary
The top 5 elements in a cell (in highest to lowest proportion) are carbon, oxygen, nitrogen, hydrogen, and phosphorous. Terrestrial (lithosphere), aquatic (hydrosphere), atmospheric, and living (biosphere). Greenhouse gases: co2, ch4, 03, h20, n2o. Carbon emission comes from the factory into the air, then goes into the soil, plants use this carbon to make food, then animals eat the plants and consume the carbon. Production of methane from organic carbon in anoxic environment. Hydrogenotrophic methanogens: produce methane from co2 and h2. Syntrophic partnership: give and take relationship between organisms. Carried out by 2 types of nitrifiers: No3 no2 no n2o n2 (anaerobic respiration). Denitrifiers are mostly bacterial heterotrophs that can use nitrate/nitrite as a terminal electron acceptor, eventually producing n2 (completing the nitrogen cycle). Nh4 + no2 n2 + 2h20. This process does not produce co2 and n2o. This process may affect marine life by depleting n sources. Synthetic nitrogen fertilizers imbalance of nitrogen reservoirs, marine dead zones.
