Why is Nitrogen important?
- It is an essential nutrient for all life-forms.
- It is a part of many molecules essential to life, like proteins, nucleic acids (DNA and RNA) and some
- It is found in other biologically important compounds such as alkaloids and
What is Nitrogen fixation?
The nitrogen molecules of the atmosphere are in their elemental form and do not easily react with other chemicals to form new compounds. Our body, and the bodies of other plants and animals, have no good way to convert nitrogen into a usable form. Hence, they cannot be directly used by the living organisms and need to be broken down into simpler forms. This is done by bacteria that convert atmospheric nitrogen into biologically usable forms in a process called nitrogen fixation.
What is the Nitrogen cycle?
The nitrogen cycle is the biogeochemical cycle by which nitrogen is converted into multiple chemical forms as it circulates in the Earth-atmosphere system.
Some species of nitrogen-fixing bacteria are free-living and some are associated with dicot plant species while some of them are also found in the roots of legumes. They have an amazing ability to convert the elemental nitrogen present in the air into nitrates and nitrites. This broken-down form of nitrogen is easily assimilated by the plants. Plants then convert these into several other forms like amino acids which help them to form proteins. When animals eat these plants these molecules are further converted into complex molecules and when the animals die, all these go
back into the soil. Some bacteria repeat the process of fixation while some bacteria help to convert the nitrogen compounds into its elemental state and thus adding nitrogen back to the atmosphere, completing the cycle.
Nitrogen cycle
 Apart from the bacteria, even lightning can convert nitrogen from the air into nitrates and nitrates. The high pressure and temperature change during lightning help to trigger this process.
