Describe the nitrogen cycle with diagram
Answers
Answer:
Nitrogen is both the most abundant element in the atmosphere and, as a building block of proteins and nucleic acids such as DNA, a crucially important component of all biological life. The nitrogen cycle is a complex biogeochemical cycle in which nitrogen is converted from its inert atmospheric molecular form (N
2
) into a form that is useful in biological processes.
Atmospheric nitrogen occurs primarily in an inert form (N2) that few organisms can use; therefore it must be converted to an organic – or fixed – form in a process called nitrogen fixation
nitrogen deposited from the atmosphere undergoes a set of changes: its two nitrogen atoms separate and combine with hydrogen to form ammonia (NH
4
+).
While ammonia can be used by some plants, most of the nitrogen taken up by plants is converted by bacteria from ammonia – which is highly toxic to many organisms – into nitrite (NO
2
−), and then into nitrate (NO
3
−). This process is called nitrification, and these bacteria are known as nitrifying bacteria.
Nitrogen compounds in various forms, such as nitrate, nitrite, ammonia, and ammonium are taken up from soils by plants which are then used in the formation of plant and animal proteins.
Nitrogen makes its way back into the atmosphere through a process called denitrification, in which nitrate (NO3-) is converted back to gaseous nitrogen (N2). Denitrification occurs primarily in wet soils where the water makes it difficult for microorganisms to get oxygen. Under these conditions, certain organisms – known as denitrifiying bacteria – will process nitrate to gain oxygen, leaving free nitrogen gas as a byproduct.
Answer:
The nitrogen cycle is the biogeochemical cycle by which nitrogen is converted into multiple chemical forms as it circulates among atmosphere, terrestrial, and marine ecosystems. ... Important processes in the nitrogen cycle include fixation, ammonification, nitrification, and denitrification.
