Natural Selection Image Map

From the sea to the critters in the sea, to the air, to the land and that which lives on it - key materials are recycled.

What Cycles Need for Energy
Where the Carbon Goes
Oxygen Likes All Elements
Water Is the Solution
Nitrogen: A Double-edged Sword
Sulphur Travels by Land and Air
Phosphorous Doesn't Have Wings

What Cycles?

Do you or your parents recycle newspapers, aluminum cans, or plastic bottles?  Nature has its own recycling processes that are used to conserve the resources it needs to keep ecosystems going.

Matter constantly flows through the different parts of an ecosystem.  Remember that the major components of an ecosystem include:  

  • Atmosphere

  • Producers - plants and bacteria

  • Consumers - animals, fungi, bacteria

  • Decomposing organic matter

  • Soil and water

Ecosystem components, as they relate to turnover of plant material.

With the background knowledge of chemical cycles explained in Toxic or Not, we can now begin to understand how all the components of an ecosystem work together to maintain a constant supply of resources. The cycles of greatest importance involve water, carbon, oxygen, nitrogen, phosphorous, and sulfur.

The Need for Energy Drives the Carbon Cycle

All living things need energy.  The sun either directly or indirectly provides energy for most of the organisms on earth.  If the sun provides energy, then why can’t we all just go lie out in the sun to get an energy boost?  In addition to getting great tans, we would save money by eliminating the need to buy food.  It sounds great, but it can’t happen because our cells do not contain chloroplasts, the site of photosynthesis in plant cells.

Photosynthesis may look like a large, intimidating word.  Let’s break it down in order to get a general idea of what it means:

Photo + Synthesis = Photosynthesis. 

"Photo" means light. Synthesis means to put together

Plants use the energy contained in this sunlight to turn carbon dioxide into energy in the form of a carbohydrate (sugar) called glucose.  

Did you know that CO2 is pumped into sodas to make them fizzy (hence the name carbonated beverage).

To summarize, photosynthesis involves two processes:

1.  Energy from the sun is turned into chemical energy

2.  The chemical energy is used to “put together” glucose from carbon dioxide “building blocks”

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