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Nitrogen Cycle

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fexotoka's version from 2018-02-26 22:23

Section 1

Question Answer
Nitrogen fixationStep in which nitrogen gas (N2) found in the atmosphere is taken to the soil by legume plant bacteria and converted into ammonia (NH3)
Nitrificationin this step gas will be broken down and separated into nitrites (NO2-) and nitrates (NO3-)
AssimilationWhen plants absorb the nitrites for them to be incorporated into the plant’s protein and nucleic acids that will later be transferred to animals and humans by consumption
AmmonificationIt happens when bodies decompose, the nitrogen goes back to the soil as ammonium(NH4) or to the air as free nitrogen
DenitrificationThe fifth and last step of the nitrogen cycle, happens when the nitrate is turned back to gaseous nitrogen by anaerobic bacteria reversing the cycle.
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Section 2

Question Answer
Free nitrogen (N2)Nitrogen in its first state (gaseous) before it goes trough the nitrogen cycle.
Nitrogen fixationProcess by which (N2) nitrogen must go to be absorbed by humans, animals and plants, it involves atmosphere (air) and lithosphere (earth) and in some cases hydrosphere (water)
Lightening fixationThe only other way for nitrogen to be transformed, the enormous energy of lightning breaks nitrogen molecules and enables their atoms to combine with oxygen in the air forming nitrogen oxides. These dissolves in rain, forming nitrates, that are carried to the earth. Atmospheric nitrogen fixation probably contributes some 5– 8% of the total nitrogen fixed.
Nitrifying bacteriaBacteria that come from the roots of legume plants, they are the ones in charge of transforming the free nitrogen (N2) to nitrites (NO2−), nitrate (NO3−) and ammonia (NH3)
Denitrifying bacteriaBacteria in charge of transforming the nitrogen found in the soil back to atmospheric nitrogen (N2)
Nitrite (NO2−)What nitrifying bacteria turn free nitrogen (N2) into trough out the second step, nitrification. Consists of one central nitrogen atom surrounded by four identical oxygen atoms in a trigonal planar arrangement
Nitrate (NO3−)What nitrifying bacteria turn free nitrogen (N2) into trough out the second step, nitrification. Consists of one central nitrogen atom surrounded by three identical oxygen atoms in a trigonal planar arrangement
Ammonia (NH3)A colorless gas with a characteristic pungent smell, the compound has one nitrogen atom and three hydrogen molecules
Ammonium (NH4)Positively charged polyatomic ion, made up by one nitrogen molecule and four hydrogen.
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Section 3

Question Answer
Acid RainForm of precipitation with acidic components (such as sulfuric or nitric acid). It is caused by sulfur dioxide (SO2) and nitrogen oxides (NOX) emitted into the atmosphere and transported by wind/air currents.
EutrophicationEnrichment of water by salts that causes structural changes to the ecosystem like increased production of algae and aquatic plants, reduction of fish species, etc. It is a serious environmental problem since it results in a deterioration of water quality.
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