1.5 Nitrogen Cycle

Nitrogen is a critical nutrient for plant and animal survival. All living things need nitrogen to build

• DNA

• Proteins

Atmospheric Nitrogen

N2

Ammonia

NH3

Ammounium

NH4^+

Nitrite

NO2^-

Nitrate

NO3-

Nitrous Oxide

N2O

Identify the main reservoir of Nitrogen

Atmosphre

Identify the form of nitrogen that is present in the atmosphere bur is not usable by plants or animals

Atmospheric Nitrogen

Identify the name of the process where nitrogen fixing bacteria or other processes convert N2 gas from the atmosphere into biologically available forms of nitrogen usable by plants

Nitrogen Fixation

Some of these plants live in soil. Others live in root nodules of plants called

legumes

In many ecosystems, the availability of nitrogen compounds limits

plant growth

Identify the step of the N cycle where plants and animals take in N and incorporate it into their bodies

Assimilation

Identify the step in the nitrogen cycle where decomposers convert the organic nitrogen into ammonium

ammonification

Identify the step of the N cycle where soil bacteria convert ammonium into nitrite and nitrate

nitrification

a natural bacterial process that converts soil or water nitrates into nitrogen gas, releasing it back into the atmosphere

denitrification