AP Environmental Science


Nitrogen Cycle

Nitrogen is a nutrient for amonio acids, proteins, and nucleic acids (such as, DNA and RNA). Nitrogen is the most limiting nutrient for plant growth. Animals recieve the nitrogen they need for metabolism, growth, and reproduction by the consumption of living or dead organic matter holding onto molecules composed partially of nitrogen. The nitrogen cycle is the biogeochemical cycle that describes the transformations of nitrogen and nitrogen containing compounds in nature. Fication is used in the nitrogen cycle to convert gaseous nitrogen into forms ueable by living oranisms. Nutrient-pour souls can be planted with legumes to enrich them with nitrogen. A necessary amount of nitrogen is fixated in ammonia chemical plants. Plant's get nitrogen from the soil, and by absorptopn of their roots as either nitrate ions or ammonium ions. Animals recieve the nitrogen they need for metabolism, growth, and reproduction by the consumption of living or dead organic matter holding onto molecule composed partially of nitrogen. Nitrates can enter groundwater because of very high solubility. When there is low energy, denitrification by bacteria occurs, when this happeneds, nitrate is converted to nitrogen gas and returned to the atmosphere.

Nitrogen Cycle Process

 Biological Fixation is when some symbiotic bacteria and some free-living bacteria are able to fix nitrogen and to absorb it as organic nitrogen. Industrial N-Fixation is when the use of a catalyst, atmospheric nitrogen and hydrogen can be combined to form ammonia. Combustion of fossil fuels come from automobile engines and thermal power plants, which usually release various nitrogen acids.

Effects

Ammonia in the atmosphere has triped as the result of human activities. It is a reactant in the atmosphere which decreases air quality and clinging on to water droplets, eventually results in acid rain. A continuous use of chemical fertilizers, ad pollution emmited by vehicles and industrial plants has been the simple ways of humans contributing to the transfer of nitrogen true gases from Earth to the atmopshere from the land to aquatic systems. Ecosystems processes can increase with nitrogen fertilizaton, buy anthropogenic inpu can result in nitrogen saturation. Onsite sewage facilities such as septic tanks and holding tanks release large amounts of nitrogen into the environment by discharge through a drainfield in to the ground. In certain areas, the soil is unsuitable to handle some or all of the wastewater, then results in, the wastewater with the contaminents enters the aquifiers. These delicious contaminants accumulate and eventually end up in drinking water.

The Bacteria

Nitrogen Fixing bacteria puts nitrite from the air into the soil. Decomposing bacteria recycles nitrite from animals/plants back into soil. Denitrifying bacteria puts nitrogen from soil back into the air.

Definitions

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Documentation of Souces

http://www.physicalgeography.net/fundamentals/9s.html

http://www.sws.uiuc.edu/nitro/biogen.asp

http://www.eoearth.org/article/Nitrogen_Cycle

http://en.wikipedia.org/wiki/Nitrogen_cycle