Transcript The Energy of Life - AVC Distance Education: Learn

The Energy of Life
Energy is the ability to do work.
Biological work that requires
energy
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Growing
Moving
Reproducing
Maintaining and repairing damaged tissues
Forms of Energy
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Energy exists in different forms:
Chemical
Radiant
Mechanical
Heat
Electrical
Nuclear
Potential Energy
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Energy can exist as stored energy called
potential energy.
Potential energy is stored in the drawn bow
Kinetic Energy
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The energy of motion.
Potential energy is converted to kinetic energy
as the arrow speeds toward its target
Thermodynamics
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The study of energy and its transformation.
The First Law of Thermodynamics
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Energy can not be created or destroyed,
although it can be transformed from one
form to another.
As far as we know, the energy present in the
universe at its formation (18 billion years
ago), equals the amount of energy present in
the universe today.
True/false?
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Organisms cannot create the energy that
they require to live.
True
The Second Law of Thermodynamics
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As each energy transformation occurs, some
of the energy is changed to heat energy that
can never again be used by any organism
for biological work.
Heat still exists in the surrounding
environment.
During energy transformation
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Some usable energy (energy available to do
work) is degraded into a less usable form,
heat that disperses into the environment.
Energy flows:
Solar
Chemical
Heat
Conclusion
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The amount of usable energy available to do
work in the universe decreases over time.
The total amount of energy in the universe
is not decreasing with time.
Entropy
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Less-usable energy is disorganized.
Entropy is the measure of this disorder.
Usable energy has low entropy.
Disorganized energy such as heat has high
entropy.
Entropy is continuously increasing in the
universe in all natural processes.
Entropy can be represented by beakers filled
with marbles of two different colors
Highly organized system
(Low entropy)
Disorganized system
(with greater entropy)
It may be
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that at some time, billions of years from
now, all energy will exist as heat uniformly
distributed throughout the universe.
If that happens, the universe will cease to
operate because no work will be possible.