The nitrogen cycle is the process by which nitrogen is converted between its various chemical forms. Nitrogen is required for all organisms as it is the essential component of DNA, RNA, and protein. However, most organisms cannot use atmospheric nitrogen hence, this cycle is important in the sense that it converts the atmospheric nitrogen into usable forms for living organisms.
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As seen from the diagram below, the carbon cycle consists of many cycles within it. These cycles consist of five important processes that are driven by microorganisms, namely:
Process #1 - Nitrogen Fixation
This is the process whereby N2 is converted to ammonium. Without this, organisms cannot attain nitrogen as they cannot use the atmospheric nitrogen. Ways nitrogen can be fixated in the biosphere include:
Process #2 - Uptake
This is the process where ammonia produced by nitrogen fixing bacteria is quickly incorporated into protein and other organic nitrogen compounds. When we eat, we are using nitrogen that has been fixed initially by nitrogen fixing bacteria.
Process #3 - Decomposition
When organisms die, or when organisms defecate, decomposers (such as bacteria and fungi) consume the organic matter or animal waste. During this decomposition process, nitrogen contained within the dead organism is converted to ammonium. Once in the form of ammonium, nitrogen is available for use by plants or for further transformation into nitrate (NO3-) through the process called nitrification.
Process #4 - Nitrification
Nitrification is whereby ammonium produced by decomposition is converted to nitrate.
Process #5 - Denitrification
The processes above remove nitrogen from the atmosphere and pass it through ecosystems. Therefore denitrification is important as it replenishes the atmosphere, by reducing nitrates to nitrogen gas.
This process can be carried out either through bacteria or the sea.
AND THE CYCLE REPEATS! :)
Done by: Yangting :D