Download Cycles of Matter

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–Why is it important to living
organisms that nutrients cycle?
–A: Cycling makes nutrients
available for other organisms to
use.
Cycles
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
Water cycle
– Who remembers the water cycle from last
year? What processes are involved?
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
Water cycle
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.
• Nitrogen – needed to make proteins
• Conversion of nitrogen into a form that is useable by plants is called
nitrogen fixation.
THE GOAL!
Atmospheric nitrogen (N2)
Nitrates (NO3)
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
Nitrogen Fixation
http://www.youtube.
com/watch?v=4NKG
S4bj7cc
The Carbon Cycle
• Carbon
• Major part of organic molecules
• Carbohydrates, proteins, fats, and nucleic acids.
• Contained within…
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•
•
•
•
animal skeletons
rocks
the atmosphere (CO2)
dissolved in oceans
fossil fuels (coal, natural gas, oil)
Carbon Cycle
http://blogs.dickinson.edu/copenhagen/files/2009/09/carbon-cycle.gif
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
• https://www.youtube.com/watch?v=
2D7hZpIYlCA
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
* 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
Phosphorus Cycle