Originally posted by PocketKings
I'm trying to explain this to my class and I don't even get it lol.
Can anyone put it in terms that my 8th grade class would understand?
Nitrogen is the key component of protein, the building blocks of life. It is basically present in the environment in 3 main forms. The main one is in the atmosphere, where it makes up over three-quarters of the gas we breathe.
The other big form is in living things, as part of the proteins that all living things contain (things like muscle tissue, enzymes - pretty much all of us that isn't water).
The nitrogen cycle explains the way nitrogen is coverted between these two main 'stores' via the 3rd form - which basically relates to some intermediate chemicals that dissolve in water.
It goes like this....
1) Nitrogen in the air is 'fixed' by bacteria that use it as fuel. Fixing simply means turning a gas into a soluble (dissolves in water) chemical so it is no longer a gas.
2) This makes it available to plants to absorb and make proteins (that is why we apply nitrogen fertilizer to plants to boost growth)
3) Animals eat plants and use this protein themselves for growth etc
4) Animals die, and other bactera break down their proteins
5) Other types of bacteria break down these soluble nitrogen products back into gas and the cycle is complete
This is a big simplification, and misses out some steps. It is also true that the cycle goes backwards as well as forwards, and is interchangable. But it does explain the basics.