First 315 words of the document:
The Nitrogen Cycle
WHAT YOU NEED TO KNOW:
Our atmosphere is 78% Nitrogen.
It can't be used by plants as it is so unreactive.
It is needed for making proteins for growth so how do the living organisms get it????
The nitrogen in our air has to be turned into nitrates so plants can use it. Animals get it by
eating these plants.
Decomposers (bacteria and fungi found in soil) break down the proteins that are found in
rotting organisms and in waste (urea in wee :/ ) and turn it into ammonia. This puts the
nitrogen compounds back in the soil. RECYCLING!
The process of turning Nitrogen from the air into the useful nitrogen compounds in the soil is
called NITROGEN FIXING. The Nitrogen is FIXED so it is useful like how cars and other stuff is
fixed so it can be used. (This can happen through lightning so much energy that the nitrogen
reacts with oxygen, or through nitrogen fixing bacteria in roots and soil.)
MORE THINGS THAT YOU NEED TO KNOW
The fab four bacteria involved in the nitrogen cycle:
DECOMPOSERS They DECOMPOSE proteins and urea, turn them into AMMONIA
NITRIFYING BACTERIA AMMONIA (from decaying matter) into NITRATES
NITROGEN FIXING BACTERIA NITROGEN (from air) into NITROGEN COMPOUNDS (useful things
DENITRIFYING BACTERIA NITRATES into NITROGEN (useless)
A bit of extra info on NITROGEN FIXING BACTERIA:
Some live in the soil, other in nodules on the roots of legume plants. Legume plants are
expert at putting nitrogen into the soil.
The legumes and bacteria have a mutualistic relationship (they're cool with each other). The
bacteria get sugar (food yum) from the plants and the plants get nitrogen compounds to
make their proteins. They both benefit.