1. Nitrogen cycle

2. Terms to know Nitrification Denitrification Ammoniafication
Assimilation
Legume
Nitrogen fixation

4. Most (~78%) of the atmosphere is nitrogen gas (N2).
Very few organisms can use this form of nitrogen. Nitrogen must be “fixed” or converted into a useable form.
A few that can are “nitrogen-fixing” bacteria, often associated with the roots of plants called legumes.
Some marine blue-green algae also fixes nitrogen, as well as lightning

5. Nitrogen Fixation N2
Nitrogen fixation is a process by which nitrogen (N2) in the atmosphere is converted into ammonium (NH4).
Bacteria on Root Nodules of Legumes

6. NITRIFICATION
Oxidation of an ammonia compound into any nitrate (NO3) or nitrite (NO2)
ammonium (NH4)
From Nitrogen Fixation .
From bacteria in soil

7. Plants absorb nitrates from the soil through the roots and incorporate the nitrogen into nucleic acids, proteins (amino acids) and more. Herbivores eat the plants and also make proteins and nucleic acids
ASSIMILATION

8. DENITRIFICATION
Converting nitrates (NO3) into atmospheric nitrogen gas (N2). Process is done by some soil bacteria & volcanic gases