1. The Nitrogen Cycle

2. What is the Nitrogen Cycle?
Nitrogen Cycle – a natural cyclic process in the course of which atmospheric nitrogen enters the soil and becomes part of living organisms, before returning to the atmosphere.

3. What is Nitrogen?
Nitrogen is a colorless, odorless, tasteless, nontoxic gas.

4. What is Nitrogen?
Nitrogen, an essential part of the amino acids, is a basic element of life.

5. What is Nitrogen?
Makes up 78 percent of the Earth’s atmosphere.

6. How does the Nitrogen Cycle work?
Atmospheric Nitrogen is carried to the earth by Precipitation.

8. How does the Nitrogen Cycle work?
Bacteria in the soil convert the atmospheric Nitrogen gas (N2), into nitrates (NO3) and ammonium ions (NH4) which can then be used by plants and fungi.
This process is called:
Nitrogen Fixation

10. How does the Nitrogen Cycle work?
The nitrogen then passes through the food chain from plants to herbivores to carnivores.

12. How does the Nitrogen Cycle work?
Animals poop …………………

14. How does the Nitrogen Cycle work?
………..and pee.
Animal wastes have high Nitrogen levels.

15. How does the Nitrogen Cycle work?
This nitrogen gets returned to the soil for decomposition by bacteria and re-use.

17. How does the Nitrogen Cycle work? SUMMARY
All organisms produce wastes and eventually die.
When an organism dies its proteins are slowly broken down into ammonia compounds, then to nitrites, and finally back to nitrates.
The nitrates can then reenter the cycle.

19. How does the Nitrogen Cycle work? SUMMARY
At various stages in the decay process, denitrifying bacteria [soil bacteria that reduce nitrates (NO3)or nitrites (NO2)to gaseous nitrogen and some nitrous oxide] can break down nitrites and nitrates, releasing nitrogen gas back into the atmosphere.

21. Assignment
Draw a diagram of the Nitrogen cycle that follows these notes.
Write an essay that explains how the nitrogen cycle works and what would happen if any link in the cycle were removed. You should be able to describe in great detail with specific examples.