Download 3.4 Nutrient Cycling

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Anchor: BIO.B.4.2 Describe interactions &
relationships in an ecosystem
◦ BIO.4.2.3: Describe how matter recycles through an
ecosystem
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Remember: living organisms are composed of
organic matter:
◦ Full of carbs, lipids, proteins & nucleic acids!
ECOLOGY
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How is matter cycled?
◦ **Remember: there is a ONEWAY flow of energy through the
ecosystem, but matter (organic
stuff) must be recycled
throughout the ecosystem!!***
 Energy is moved through parts of an
ecosystem through biogeochemical
cycles
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 Ex: water, sulfur, phosphorus,
carbon, nitrogen cycles
decomposers
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Nutrients: molecules that
an organism needs to
sustain life
◦ Used to build tissues and
carry out metabolism
 Ex: CHONPS
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decomposers
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Hydrologic Cycle
◦ Importance
 Every living thing requires WATER
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Hydrologic Cycle
◦ Key Processes:
 Evaporation: liquid  gas
 Transpiration: evaporation
from plant leaves
 Condensation: gas  liquid
 Precipitation: rain, sleet, snow,
hail
 Runoff: water moving downhill
into streams/rivers
 Infiltration: water soaking into
the soil
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Hydrologic CycleCondensation
Precipitation
Transpiration
Evaporation
Runoff
http://earthguide.ucsd.edu/earthguide/diagrams/watercycle/
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Carbon Cycle
◦ Importance
 Used in making living tissues and animal skeletons
 Regulates temperature in the atmosphere (carbon
dioxide)
 Plants  photosynthesis  pass along glucose in food
webs
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Carbon Cycle
◦ Key Processes:
 Photosynthesis: how autotrophs produce glucose
(food) while removing carbon dioxide from the air
 CO2 + H2O + light  C6H12O6 + O2
 Cellular Respiration: how all organisms break down
food to get ATP energy and release carbon dioxide
in the air
 C6H12O6 + O2  CO2 + H2O + ATP
 ATP is a molecule used for energy
◦ Decomposition: bacteria and fungi break down
dead organisms and release their nutrients in
the soil and carbon dioxide in the air
 Creates fossil fuels with extreme pressure
◦ Combustion: Burning of fossil fuels (coal, oil,
natural gas) and trees releases carbon dioxide into
the air and this can lead to global warming
http://www.npr.org/2007/05/01/9943298/episode-1-its-all-about-carbon
CO2
Burning
FF
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CR by
plants/animals
Fossil Fuel
formation
Burning
plants
Decomposition
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Nitrogen Cycle:
◦ Importance:
 All organisms require nitrogen to make amino
acids that are used to build proteins
◦ Forms of Nitrogen:
 Nitrogen Gas (N2): in atmosphere
 Ammonia (NH3), Nitrate (NO3-), Nitrite (NO2-):
found in wastes & in decaying organisms
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Nitrogen Cycle:
◦ Key Processes:
 Nitrogen fixation: convert nitrogen gas into
ammonia
 N2
NH3
 Performed by bacteria found in the soil or in
roots of plants
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Nitrogen Cycle:
◦ Key Processes:
 Ammonification: ammonia (NH3) is
converted to nitrate (NO3-) and nitrite (NO2-)
OR
 NH3
NO3 NH3
NO2 Done by bacteria in the soil
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Nitrogen Cycle:
◦ Key Processes:
 Assimilation: plants use nitrates or nitrites
made for them by the bacteria or animals
consume nitrates and nitrites by eating
plants
 Nitrogen is in organism and can be used to
make amino acids
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Nitrogen Cycle:
◦ Key Processes:
 Detrification: nitrates (NO3-) are changed
into nitrogen gas (N2)
 NO3N2
 Nitrogen gas is released back into atmosphere