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Why
Our Bodies Need Air

Just
as air is needed to burn fossil fuels and release their energy
(such as coal and natural
gas), our bodies need air to burn the fuel of foodstuffs to
release energy. What is
it in air that is needed? .... OXYGEN.
Why
is this important for mitochondria?
Mitochondria are the cell components
that use oxygen to liberate the chemical energy of foodstuffs
and trap it in energy storage compounds that cells can use
later.
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What
are mitochondria? and What do they do?
Mitochondria are the energy factories of the cells. Their job is
to "burn" the fuel (which we get from food) and capture some of
the energy in high-energy chemical bonds that
can be used later for various cell functions. See
the diagram below.

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| The diagram shows the structure of mitochondria
and the relationships of the parts on the left. On the right,
the diagram shows that sugars (glucose) are
burned in two ways. Glucose, a sugar with 6 carbon atoms gets
first gets broken down to a 3-carbon molecule (pyruvic acid) in
a stage of chemical reactions called
glycolysis. This
releases a little energy, but if oxygen is present, the pyruvic
acid can then be burned to release a great deal of energy in a
stage of chemical reactions called that give off carbon dioxide and water
as waste products.
In the presence of oxygen, the energy is
extracted in a cycle of chemical reactions wherein the first molecule in
the cycle gets re-built at the end of the cycle. We call this
the "Krebs' cycle."
Because the reactions cycle, the process sustains itself and
continually produces energy as long as glucose and oxygen are
present. Neat!
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