Question

What are the steps involved in the nitrogen cycle?

Answer 1

Nitrogen:

1. The earth’s atmosphere contains about 78% nitrogen in the gaseous phase.
2. As Nitrogen is essential for many biological processes as nitrogen is an essential component of amino acids, enzymes, proteins, and nucleic acids
3. The nitrogen cannot be utilized directly by living organisms such as plants so it is changed into nitrites and nitrates are termed nitrogen fixation.

Nitrogen cycle:

• The Cycle describes the continuous transformation of atmospheric nitrogen into usable forms and returns to the atmosphere as nitrogen.

The Steps Involved in Nitrogen Cycle are:

1. Nitrogen fixation :

• The conversion of atmospheric, industrial, or biological nitrogen into such usable forms which can be utilized by living organisms is called Nitrogen fixation.
• Nitrogen fixation takes place in three ways :
• Atmospheric Nitrogen fixation:

• It takes place through photochemical and electrochemical, reactions due to lightning and thunderstorms

• Biological Nitrogen fixation:

• It takes place through nitrogen-fixing bacteria such as Azotobacter, Azospirillum, and Alage such as Anabaena.

• Industrial Nitrogen fixation:

• It takes place in industries at high temperatures and high pressure.

2. Assimilation:

• The nitrates and nitrites are absorbed by green plants to produce the organic compounds of nitrogen.
• The nitrates are reduced to ammonia that combines with organic acids to form amino acids, proteins, and nucleic acids.

3. Ammonification:

• The decomposition of proteins of dead animals and plants to ammonia in the presence of ammonifying bacteria such as Bacillus ramosus and Bacillus vulgaris.

4. Nitrification:

• The process of oxidation of ammonia into nitrites and nitrates in the presence of nitrifying bacteria such as Nitrosomonas and Nitrobacter
• The ammonia is first oxidized into Nitrite in the presence of Nitrosomonas bacteria and this nitrite is further oxidized to Nitrate in the presence of Nitrobacter bacteria .:

5. Denitrification:

• The process of conversion of nitrates and nitrites into molecular nitrogen in the presence of denitrifying bacteria such as Thiobacillus denitrificans is called Denitrification.