Nutrient Cycles

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Nutrient Cycles

• Water cycle
• Carbon cycle
• Nitrogen cycle
• Phosphorus cycle

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Water cycle
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Water cycle

• All living things need water because the
  cytoplasm in cells is composed mostly of water.
• The chemical reactions that support life must
  take place in water
• The electrical impulses produced by nerves are
  transmitted through water.

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How does water move through the environment?

• Precipitation water falls from the sky as rain,
  snow or sleet
• Evaporation water returns to the atmosphere as
  a gas
• Waste animals release liquid waste
• Respiration water is product of cellular
  respiration
• Runoff and streams carry water from place to
  place in the environment.

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Why is carbon Important?

• All of the macromolecules contain carbon.
• Carbon is used to make sugars which provide
  living things with energy.
• The carbon containing macromolecules are the
  building blocks of all life.

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How does carbon move through the environment?

• Photosynthesis pulls CO2 from the air and uses
  it to make sugars.
• Consumption one organism eats another and gets
  its carbon.
• Respiration cellular respiration releases CO2
  back to the air as it breaks down sugars

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How does carbon move through the environment?

• Decomposition as dead organisms are broken
  down, the carbon is released to the soil or back
  to the air.
• Deposition the remains of dead organisms can be
  converted to fossil fuels
• Burning releases CO2 back to the air when
  organisms or fossil fuels are burned.

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Why is Nitrogen important?

• Nitrogen is an element that is found in amino
  acids.
• Amino acids join together to form proteins
• Proteins help living things carry out life
  processes.

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How does Nitrogen move through the environment?

• Nitrogen gas makes up most of our air but
  organisms cant use it in this form.
• Nitrogen fixation bacteria, lightning and
  fertilizer factories take Nitrogen from tha air
  and convert it into forms organisms can use
• Plants take in nitrates from the soil to make
  amino acids

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How does Nitrogen move through the environment?

• Consumption organisms eat each other and obtain
  their nitrogen
• Decomposition and waste return nitrates to the
  soil.
• Denitrification bacteria return nitrogen back
  to the air.

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Why is phosphorus important?

• Phosphorus is found in nucleotides.
• Nucleotides join together to form nucleic acids
• Nucleic acids control cell functions

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How does phosphorus move through the environment?

• Consumption organisms eat each other and obtain
  phosphorus
• Decomposition and waste return it to the soil
• Plants acquire P from the soil
• Weathering rain breaks down rocks and release
  the phosphorus they contain.