Download Notes: The Nitrogen Cycle

 THE NITROGEN CYCLE
- All organisms need to make proteins and nucleic
acids, both which contain nitrogen.
- Nitrogen gas (N2) = 80% of the atmosphere.
A. Nitrifying bacteria that live on the roots of plant
and in the soil, “fix” the nitrogen into a form called
nitrate
B. Plants use the nitrate to make amino acids.
- Plants don’t eat protein to get the a.a monomers
they need to make their own protein, so they have
to get these a.a. another way…
C. Consumers (herbivores & omnivores) eat plants and
use the nitrates in plants to make protein and DNA.
D. Decomposers break down dead plants and animals to
release nitrogen back to the soil.
E. Denitrifying bacteria finally turn the nitrogen in
the soil back into nitrogen gas (N2) and return it to
the atmosphere.