Biogeochemical

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Biogeochemical Cycles
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Why are Biogeocycles Important

• Each Living organism needs nutrients
• a. for growth
• b. to carry out essential life functions
• Recycling of nutrients is necessary for
  ecosystems to continue functioning
• Also Prevents some chemicals from accumulating
  and reaching toxic levels

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Essential Biogeocycles

• 1. Water cycle
• 2. Oxygen-Carbon Dioxide cycle
• 3. Nitrogen cycle
• 4. Phosphorus cycle

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Water Cycle
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Water cycle key points

• Transpiration water from plants
• Condensation water in clouds, atmosphere
• Precipitation as water is released from clouds
  as rain, snow, sleet etc.
• Evaporation result of heat water enters
  atmosphere this way

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Oxygen-Carbon Dioxide Cycle
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Carbon cycle Key points

• Photosynthesis used carbon to make glucose
  takes Carbon from atmosphere
• Cellular respiration releases carbon into
  atmosphere through breathing
• Decomposition releases carbon through decay
• Fossil fuel burning of fossil fuels releases
  carbon

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Nitrogen Cycle
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• All organisms require nitrogen to make amino
  acids which are used to make proteins.

1. Many different forms of nitrogen in the
biosphere
a. Nitrogen gas N2 (78 of atmosphere)
i. Only certain types of bacteria can use this
form of nitrogen directly
ii. Found in soil and on legume roots, they
change the N2 to ammonia in a process called
nitrogen fixation.
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b. Ammonia NH3
i. Another type of bacteria that lives in
the soil change NH3 to nitrates and nitrites
ii. When organisms die, they decompose and
leave behind ammonia
c. Nitrate ions NO3- (found in waste products)
i. Found in waste products and decaying matter
ii. Form used to make proteins
iii. Another type of bacteria in the soil
converts nitrates to nitrogen gas in a
process called denitrification
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Phosphorus Cycle
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All organisms require phosphorus because it
forms part of life-sustaining molecules like
DNA/RNA
1. Not very common in the biosphere
Does not enter the atmosphere
Remains mostly in rocks, minerals, and ocean
sediments

Released when matter erodes/wears away
Dissolves in the water where it is taken up by
organisms and plants