1. Cycles Of Matter
WATER
CARBON
NITROGEN
End Show

2. The Water Cycle
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4. Precipitation Water that has condensed in the air forms clouds.
Drops fall to Earth and accumulate in oceans and lakes.
Water Cycle

5. Using Water Plants and animals need water to live.
Water is pulled from bodies of water or from the ground (groundwater).
The Water Cycle

6. Transpiration
Plants and animals return water to atmosphere through transpiration.
Animals return water to ground and bodies of water through urine.
The Water Cycle

7. Evaporation
Water from oceans, lakes, and other bodies of water re-enters the atmosphere through evaporation.
The Water Cycle

8. The Carbon Cycle
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9. Back to the Carbon Cycle
Photosynthesis
Plants use CO2 from the atmosphere, H2O, and radiant energy to make high-energy carbon molecules in the Chloroplasts
CO2 + H20  C6H12O6 + O2
Back to the Carbon Cycle

10. Respiration
CO2 is released through aerobic respiration (breathing, for example)
This occurs when glucose is converted into cellular energy in the Mitochondria of eukaryotic cells
C6H12O6 + O2  CO2 + H2O + energy
The Carbon Cycle

11. Back to the Carbon Cycle
Gas Exchange
CO2 is exchanged between the air and water
Warm water holds more CO2
Back to the Carbon Cycle

12. Decomposition
When organisms die and decay, the carbon molecules in them enter the soil.
Microorganisms break down the molecules, releasing CO2
The Carbon Cycle

13. Back to the Carbon Cycle
Pollution
Remains of dead organisms are converted into fossil fuels (over millions of years!)
Combustion of fossil fuels and wood releases CO2
Back to the Carbon Cycle

14. The Nitrogen Cycle
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15. Back to the Nitrogen Cycle
Nitrogen In the Air
Lightning and bacteria convert atmospheric nitrogen into nitrates (NO3) and ammonia (NH3)
The air we breathe is about 78% nitrogen in the form of N2 gas and about 21% oxygen in the form of O2 gas.
Back to the Nitrogen Cycle

16. Back to the Nitrogen Cycle
Nitrogen in Plants
Plants receive their nitrogen through the soil.
Nitrogen-fixing bacteria convert the nitrogen in the air and decaying material into nitrogen compounds that plants can utilize.
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17. Back to the Nitrogen Cycle
Nitrogen in Animals
When animals die their decomposing bodies add the nitrogen back into the soil.
Animals also add nitrogen to the soil through feces and urine.
Animals receive nitrogen from the plants they eat or from other animals that eat plants.
Back to the Nitrogen Cycle

18. Back to the Nitrogen Cycle
Return to Atmosphere
Nitrogen compounds break down into gas and return to air
Back to the Nitrogen Cycle

19. Nitrogen in Soil and Water
Runoff of nitrates in fertilizers enters groundwater and soil.
Denitrification is an important step in the nitrogen cycle where nitrogen is released back into the atmosphere.
Nitrates are water-soluble and leach out of the soil, flowing into groundwater and collecting in lakes and wetlands.
Back to the Nitrogen Cycle

20. Back to the Nitrogen Cycle
Man and Pollution
Fertilizers – nitrogen rich molecules made by man to improve the health and productivity of plants
Man made pollution such as vehicle exhaust, power-plant exhaust, man made fertilizers and large-animal feeding operations are all sources of nitrogen emissions.
Nitrous Oxide from burning fossil fuels falls as Nitric Acid in rainwater
Back to the Nitrogen Cycle