Transcript Nutrient Cycles

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 can’t 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.
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