Nitrogen and life

DNA, RNA and Protein
Exploring life's origins

Elementary nitrogen N₂ has extremely strong atomic bonding that living things have great difficulty in breaking it into something useful. So what does the plentiful nitrogen in atmosphere mean to organic life?

As far as I know, it has no role  in breathing of animals or in the photosynthesis of plants. Or has it?

Well, a little study shows that nitrogen is of crucial importance to all life as we know it because it is a significant part in the compound we call amino acid and it is essential to organisms also for other reasons.



Wikipedia informs us [read the entire article]

• Nitrogen occurs in all living organisms, primarily in amino acids and thus proteins and in the nucleic acids (DNA and RNA). 
• The human body contains about 3% by weight of nitrogen, the fourth most abundant element after oxygen, carbon, and hydrogen. 
• Nitrogen resides in the chemical structure of almost all neurotransmitters, and is a defining component of alkaloids, biological molecules produced as secondary metabolites by many organisms. 

Crucial for any life on Earth 
Nitrogen is a component in all amino acids, as incorporated into proteins, and is present in the bases that make up nucleic acids, such as DNA and RNA.

In plants, much of the nitrogen is used in chlorophyll molecules, which are essential for photosynthesis and further growth.

Although Earth’s atmosphere is an abundant source of nitrogen, most is relatively unusable by plants. Chemical processing, or natural fixation (through processes such as bacterial conversion — see rhizome), are necessary to convert gaseous nitrogen into forms usable by living organisms, which makes nitrogen a crucial component of food production.

The abundance or scarcity of this "fixed" form of nitrogen, (also known as reactive nitrogen), dictates how much food can be grown on a piece of land.
wikipedia