2. Identify processes that cycle in the Earth Identify processes that cycle in the Earth Carbon Carbon Nitrogen Nitrogen Water Water The Nitrogen Cycle N is for Nitrogen

3. The Nitrogen Cycle

4. Organisms use the Element Nitrogen to build protein and build cells

5. Nitrogen gas makes up 78% of the atmosphere, but this type of nitrogen cannot be used by living things. Nitrogen gas makes up 78% of the atmosphere, but this type of nitrogen cannot be used by living things.

6. Nitrogen cycles from living to non-living things. N moves from air to soil, from soil to plants and animals, and back to air again.

7. Grass NitrogenFixingBacteria DecomposingBacteria DenitrifyingBacteria Nitrogen in the Air Nitrates in the soil Nitrates absorbed by plant material Dead organisms and animal waste The Nitrogen Cycle Cow eats

8. Grass NitrogenFixingBacteria Nitrogen in the Air Nitrates in the soil The Nitrogen Cycle Part 1

9. Part 1: Nitrogen Fixing Bacteria Remove Nitrogen from the air Remove Nitrogen from the air These bacteria live in soil and on the roots of certain plants. These bacteria live in soil and on the roots of certain plants.NFB

10. Examples of Nitrogen fixing bacteria Bacteria convert nitrogen gas into usable nitrate compounds Bacteria convert nitrogen gas into usable nitrate compounds Nitrate compounds = Any compound that has nitrogen (N) Examples: NH 4 – AmmoniaNO 2 – Nitrous Oxide HNO 3 – Nitric AcidFertilizers Plants absorb these compounds and are eaten by animals Plants absorb these compounds and are eaten by animals Part 1 of the Nitrogen Cycle:

11. Bacteria change N into compounds that plants need to grow. Bacteria change N into compounds that plants need to grow.

12. Grass DecomposingBacteria Nitrogen in the Air Nitrates in the soil Nitrates absorbed by plant material Dead organisms and animal waste The Nitrogen Cycle Cow eats Part 2

13. Animals eat plants and the Nitrogen compounds become part of the animal. Animals eat plants and the Nitrogen compounds become part of the animal. Animals return N to the soil as urine and when they die and decompose. Animals return N to the soil as urine and when they die and decompose.

14. Example of dead organisms beginning to decay Decomposing –breaking downDecomposing –breaking down Nitrates into the soil

15. Grass DenitrifyingBacteria Nitrogen in the Air Nitrates in the soil The Nitrogen Cycle Part 3

16. After N enters the soil…. Chemical processes release N back into the atmosphere. Chemical processes release N back into the atmosphere.

17. Part 3 – Denitrifying bacteria Bacteria converts nitrates into nitrogen gas (atmospheric) puts nitrogen BACK INTO the atmosphere. puts nitrogen BACK INTO the atmosphere.

19. The Nitrogen Cycle– refresh How much nitrogen (%) is in the atmosphere How much nitrogen (%) is in the atmosphere Are you (humans) part of the nitrogen cycle ? Are you (humans) part of the nitrogen cycle ? How does nitrogen get into the atmosphere ? How does nitrogen get into the atmosphere ? What would happen to our atmosphere if What would happen to our atmosphere if “parts” of the nitrogen cycle were missing ?? “parts” of the nitrogen cycle were missing ?? What “part” of the nitrogen cycle are YOU What “part” of the nitrogen cycle are YOU in ??? in ???

20. What IF ?? How would the earth be if there were no denitrifying bacteria??????? denitrifying bacteria??????? How would the % of nitrogen in our atmosphere How would the % of nitrogen in our atmosphere change if there were no nitrogen fixing change if there were no nitrogen fixing bacteria ?? bacteria ?? Have you eaten any nitrogen lately? – Give some Have you eaten any nitrogen lately? – Give some examples examples Where do you fit into the nitrogen cycle ?? What is a nitrate ? What is a nitrate ?