Nitrogen Cycle

by Diana Pineda

What is the nitrogen cycle?

The series of processes by which nitrogen and its compounds are inter-converted in the in the environment and in living organisms, including nitrogen fixation and decomposition.


Steps of the cycle

  1. Nitrogen Fixation - the chemical processes by which atmospheric nitrogen is assimilated into organic compounds, especially by certain microorganisms as part of the nitrogen cycle.
  2. Nitrogen Assimilation - the formation of organic nitrogen compounds like amino acids from inorganic nitrogen compounds present in the environment.
  3. Ammonification - decomosition with production of ammonia or ammonium compounds especially by the action of bacteria on nitrogenous organic matter.
  4. Nitrification - the biological oxidation of ammonia or ammonium to nitrite followed by the oxidation of the nitrite to nitrate.
  5. Denitrification - reduction of nitrates or nitrites commonly by bacteria (as in soil) that usually results in the escape of nitrogen into the air.

Why it's important

The nitrogen cycle provides nitrogen to the ecosystem from the atmosphere, ground and oceans. Nitrogen is an important component of complex molecules such as amino acids and nucleotides, which lead to the creation of proteins and DNA, the building blocks of all life.