1. nitrogen cycle nitrogen cycle
Discuss

2. A series of events that repeat, with no beginning or end.
What is a cycle?
A series of events that repeat, with no beginning or end.
Discuss

3. Why is Nitrogen important to us?
Nitrogen is a component of the proteins and nucleic acids in our bodies.
Discuss

4. 78% of the earth’s atmosphere colorless, odorless gas
Nitrogen is an element. N
What is
nitrogen?
rare in soil
78% of the earth’s atmosphere
major component
of DNA
colorless, odorless gas

5. 4 processes Nitrogen Fixation Denitrification Nitrification
Ammonification

6. Where does nitrogen come from?
Nitrogen must be converted -fixed - into useable compounds.
Although nitrogen is abundant in the atmosphere,
organisms can not use N2 in its gas state. N2
Where does
nitrogen
come from?

7. Nitrogen Fixation
Nitrogen Fixation is the process that causes the nitrogen molecules found in the atmosphere to break apart so they can combine with other atoms.

8. There are 2 kinds of bacteria that move nitrogen through the nitrogen cycle.
bacteria that change nitrogen from a gas to a solid.
bacteria that changes it from a solid to a gas.
Some bacteria live in the soil and others live in the roots of plants

9. Plants can absorb nitrate solids through their roots.
Energy from lightning during a thunderstorm converts N2 (gas) into nitrate solids, NO3.
Plants can absorb nitrate solids through their roots.
Bacteria convert nitrogen gas into nitrate solids, NO3. N2 N2 N2 N2 N2
nitrates
nitrates
nitrates
nitrates N2

10. Other bacteria in the soil break down nitrate solids (NO3) back into N2 (gas).

11. Denitrification
Denitrification is the process in which bacteria in the soil convert nitrates into nitrogen gas.

12. nitrates nitrates nitrates nitrates

13. the bacteria or lightening
Discuss
What would happen if
the bacteria or lightening
were removed from the
nitrogen
cycle?

14. Denitrification would not
Discuss
Denitrification would not
occur. The nitrogen
would stay locked up
as a gas.

15. Plants and animals contain nitrogen compounds
Plants and animals contain nitrogen compounds. Decomposers break down biotic organisms and release the nitrogen compound in the form of ammonia (NH4)
Animal wastes decompose, adding nitrogen in the form of ammonia (NH4) back to the soil. N2 N2 N2 N2
waste
decomposers
ammonia
nitrates N2

16. Ammonification is the process in which decomposers (bacteria and fungi) convert amino acids from dead animals and wastes into ammonium.
Ammonification

17. Other bacteria convert ammonia back into nitrate solids.
waste
decomposers
ammonia
nitrates N2

18. Nitrification is the process in which bacteria convert ammonium into nitrates.

19. N2 N2 N2 N2
waste
decomposers
ammonia
nitrates N2

20. Explain what causes the nitrogen cycle to continually change.
Discuss
Explain what causes
the
nitrogen cycle to
continually change.