Transcript Cycles notes

Water cycle
Carbon/Oxygen Cycle
Nitrogen Cycle
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W.C. is a continuous process in which water
moves from Earth’s surface into the
atmosphere and back.
There are 3 main parts
◦ Evaporation: the process by which liquid water
becomes a gas
◦ Energy is needed in order for evaporation to take
place
◦ This energy comes from: THE SUN
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Condensation: the process by which water
vapor becomes liquid.
◦ Energy is released when condensation occurs
◦ Water droplets collect on dust to form clouds
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Precipitation: rain, snow, sleet, hail falling
from the sky
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Producers and consumers combine to recycle
carbon and oxygen
◦ Producers take in carbon dioxide from the air
during photosynthesis and store it and produce
oxygen as a waste product
 They use it to make sugars and starches (FOOD)
 Ex. glucose
◦ Consumers eat the producers and absorb the
carbon food molecules
Consumers take in this food and through the
process of respiration create carbon dioxide as a
waste product.
When consumers die, decomposers break down
the remaining carbon and return it to the soil.
Decomposers also create carbon dioxide.
Any type of burning of fossil fuels also releases
Carbon dioxide into the air.
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HOW HAVE WE CHANGED THE CARBON/OXYGEN
CYCLE?
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The nitrogen cycle moves nitrogen from the
air to the soil, into living things and back into
the soil and back into the air.
Most organisms can’t use “Free” nitrogen
(gas)
Nitrogen Fixation: this is the process that
changes “free “ nitrogen into useable nitrogen
Most nitrogen fixation is done by bacteria
(commonly found on plant roots)(legumes)
Once nitrogen has been “fixed” it can be used
by organisms.
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Plants and animals absorb the nitrogen
Decomposers break down their waste and
dead plant material and return the nitrogen
back to the soil
Bacteria then absorbs the nitrogen and
converts it back into “Free” nitrogen gas by
the process of denitrification.
Nitrogen can cycle through plants and
animals many times but eventually is
returned to the air