1. QUICK! Why is it important to living organisms that nutrients cycle?
A: Cycling makes nutrients available for other organisms to use.

2. Cycles Transforming energy into usable forms
Biogeochemical cycle- exchange of matter through the biosphere.
*Matter cannot be created or destroyed!!!*
Cycling of nutrients in the biosphere involves:
Matter in living organisms
Physical processes found in the environment
Transforming energy into usable forms

3. Water cycle
Who remembers the water cycle from last year? What processes are involved?

4. Water Cycle
Water is constantly evaporating into atmosphere (water vapor)
Vapor rises, cools, forms clouds (condensation):
90% of water vapor evaporates from ocean, 10% from surface of plants (transpiration).
Water falls from clouds in form of precipitation

5. Water cycle

6. Nitrogen Cycle
*Nitrogen enters the food web when plants absorb nitrogen compounds from soil*
Consumers get nitrogen by eating plants or animals that contain nitrogen. 6

7. Atmospheric nitrogen (N2) Nitrates (NO3)
Nitrogen – needed to make proteins
Conversion of nitrogen into a form that is useable by plants is called nitrogen fixation.
-animals and plants cannot use nitrogen directly from the atmosphere
-nitrogen gas captured by bacteria, convert into usable form
THE GOAL!
Atmospheric nitrogen (N2)
Nitrates (NO3) 7

8. Nitrogen Cycle (cont.)
Nitrogen is returned to the soil in several ways:
1. Animals urinate
2. Organisms die (decomposers!)
3. Lightning
Organisms convert ammonia into usable nitrogen compounds. (Nitrification)
Fixed nitrogen converted back to gas and reenters atmosphere (Denitrification)
In the soil

9. Nitrogen Fixation 9

11. The Carbon Cycle Carbon Contained within…
Major part of organic molecules
Carbohydrates, proteins, fats, and nucleic acids.
Contained within…
animal skeletons
rocks
the atmosphere (CO2)
dissolved in oceans
fossil fuels (coal, natural gas, oil)

12. Carbon Cycle http://blogs. dickinson

13. Human Impact Fossil fuels release carbon stores very slowly
Burning anything releases more carbon into atmosphere — especially fossil fuels
Increased carbon dioxide in atmosphere increases global warming
Fewer plants mean less CO2 removed from atmosphere

15. Phosphorous Cycle Phosphorous
essential to organisms as it is part of molecules such as DNA and RNA.
Remains mostly on land and in the ocean as inorganic phosphate- usually in rocks or soils.
Rocks and sediments release phosphate as they wear down

16. * Plants bind phosphate into organic compounds when they absorb it from the soil or water.
* Organic phosphates make their way through the food web to the rest of the ecosystem

17. Phosphorus Cycle