biogeochemical cycles. the movement of nutrients from the non- living world into living organisms,...
Post on 01-Jan-2016
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Biogeochemical Cycles•The movement of nutrients from the non-living world into living organisms, and then back again.
• Almost all life is based on carbon.
• The carbon cycle is a closed cycle. The total amount of carbon does not change.
• Carbon moves between living things, the atmosphere, inside the earth as fossil fuels, the soil and the oceans.
Sinks and Sources• Sinks store carbon. Examples are
the soil, the atmosphere, the ocean, and rocks.
•Sources release carbon. Examples are burning fossil fuels, animal respiration, methane production
Balance?• If sinks and sources are in
balance, the carbon stays in balance.
• An overload in the atmosphere (CO2) can cause global warming.
Plants & Carbon•CO2 is essential for plants, algae, and some bacteria.O2 is released into the atmosphere by plants and algae. (Carbon Source)
Living plants convert CO2 to O2 and carbon through photosynthesis
sun and chlorophyll6CO2 + 6H2O----»C6H12O6 + 6O2
Carbon + water sugar+ oxygenWhen dead plants decompose, carbon returns to the earth; dead plants that do not decompose may be burned, releasing carbon dioxide.
What are fossil fuels?
The remains of plants that do not decompose. (Carbon Sink)
When fossil fuels in the form of coal, oil, or gasoline are burned, carbon returns to the atmosphere as carbon dioxide gas. (Carbon Source)
What part do animals play in the oxygen-carbon dioxide cycle?Breathing animals take in oxygen and release carbon dioxide into the air. (Carbon Source) As dead animals decay, carbon returns to the earth. (Carbon Sink)
The Nitrogen cycle is a closed cycle.Nitrogen helps to support life by building proteins and other body chemicals.
•As an organism decays, carbon returns to the earth and soil bacteria produce nitrogen.
•When coal or gasoline is burned, carbon dioxide and nitric oxides are released into the air.
What is nitrogen fixation?
Bacteria that live on the roots of plants remove pure nitrogen from the air and release it into the soil.
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Nitrogen in the air can not be used directly by most organisms. To be useful, nitrogen is removed from the air and combined with other elements to form nitrogen compounds. This process is called nitrogen fixation.
What two ways form pure nitrogen gas?1. By bacteria during nitrogen fixation2. By denitrifying bacteria
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