Nitrogen cycle:
Now, The reason you clicked this blog was to know about nitrogen cycle and gain some knowledge from our science specials week blogs. So, to make you curious, do you know what nitrogen is? If not, then don't worry, this blog is especially made for you!
So, let's start!
What is Nitrogen?
To understand what nitrogen is, we would need to have a glimpse in the periodic table of elements. Well, nitrogen is the seventh element in the periodic table with atomic number seven. Also, it is a gas. So, it does make a lot of sense when you are talking about a nitrogen cycle thing. So, for starters, nitrogen is a very useful gas which can be utilised by animals and plants successfully to get nourishment! Nitrogen constitutes more than 75% of the air! Ooh! That must be a lot because everyone breathes air and that means more than seven billion people on earth are breathing air which is about 3/4 filled with nitrogen only. Then what about oxygen that we hear is very essential? Well, air too has oxygen in it which is about 20-22% of the air. And what's what we breathe. To add some more, air has small amounts of this nasty gas carbon dioxide.
Why do organisms even need NITROGEN?
Organisms use nitrogen to produce nucleic acids, amino acids and proteins. Nitrogen mainly exists as gas in the air. Nitrogen also exists in the organic matter in soils and the oceans. Nitrogen is often the most limiting nutrient for plant growth. Its because-plants take up nitrogen only in 2 forms.
1) Ammonium ion (NH4+)
2) Nitrate ion (NO3-)
Plants usually take Nitrate ions because more Ammonium ions is very toxic for them!
So, now as we know why animals and plants need NITROGEN as it is a very useful gas for them, we are now in a position to understand the NITROGEN CYCLE!
NITROGEN CYCLE
Animals recieve N {Nitrogen} by the consumption of living or dead, organic matter contacting molecules composed partially of nitrogen. Two nitrogen oxides are found in the air as a result of interaction with oxygen.
The N2 with react with O2 only in the presence of high temperatures and pressures that are found lightening bolts and in combustion reactions in powerful plants or internal combustion engines.
Image By : Byju's The Learning App. {Only for explanation purposes (only)}.
Nitric Oxide (NO) and nitrogen dioxide (NO2) are formed under these conditions!
NO2 (Nitrogen dioxide) + H2O (Rain water) = Nitric acid {HNO3} !
What a reaction!
(N) in the air becomes a part of biological matter mostly through the actions of bacteria and algae in a process known as nitrogen fixation.
Legumes such as clover, alfalfa and soybeans from the nodules of the roots where nitrogen fixing bacteria take nitrogen from the air and convert it into ammonia {NH3}.
Then,
[NH3 gets converted to NO2- (Nitrite Ions) and then these get converted to NO3- (Nitrate Ions)]
And plants utilise these Nitrate ions as a nutrient for growth.
Ammonia is also made through a synthetic process called the Haber's Process.
In Haber's process, nitrogen and hydrogen are reacted under great pressures and temperatures in the presence of a catalyst to make ammonia.
Ammonia may be further processed with oxygen to make nitric acid. Ammonia and nitric acid produce ammonium nitrate which may be used as a fertilizer. Animal wastes when decomposed also return to the earth as nitrates.
To complete the cycle, other bacteria in the soil carry out a process known as denitrification which converts nitrates back to nitrogen gas.
And the side product of this reaction is nitrous oxide or N2O.
This gas is also known as the laughing gas. It also acts as a mild anaesthetic.
Its also a green house gas contributing to the global warming.
Rhizobium and blue green algae cyanobacteria helps in converting Nitrogen to ammonia.
Rhizobium lives in the root nodules of leguminous plants and cyanobacteria lives in water.
Both are capable of fixing atmospheric nitrogen in air.
That's amazing!
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I hope you LEARNED a lot from here.
Share it with your friends and relatives to spread this knowledge.
Thanks for reading!
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