Ch. 8 Energy in a Cell
All living organisms need energy
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Cell Energy
All living organisms must be
able to obtain energy from
the environment in which
they live.
Plants and other green
organisms are able to trap
the light energy in sunlight
and store it in the bonds of
certain molecules for later
use.
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Cell Energy
Chemotrophs capture
chemical energy in covalent
bonds.
Consumers cannot use
sunlight directly.
They eat green plants or
other autotrophs. In that
way, they obtain the energy
stored in plants and other
producers.
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Autotrophs & Heterotrophs
• Autotrophs
(auto=self
troph= to feed)
• are the producers
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• Heterotrophs
(hetero=other
troph = to feed)
• are the consumers
Living creatures use ENERGY
• Metabolism
≡ all the reactions an
organism perform to make & use energy
• eating & digestion & elimination of
waste
• synthesis ≡ building molecules
(could be photosynthesis)
• cellular respiration = making energy
mitochondria
Chloroplasts
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Work and the need for energy
• Active transport, cell division, movement of flagella
or cilia, and the production, transport, and storage of
proteins are some examples of cell processes that
require energy.
• The molecule in cells that is a quick source of energy
for any organelle is Adenosine TriPhosphate (ATP).
ATP
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ATP structure
• ATP is composed of adenine (a nitrogenous base)
and ribose, (a sugar also found in RNA), along with
three attached phosphate groups.
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ATP shuttles chemical energy and
drives cellular work
• Hydrolysis of ATP releases energy by transferring its
third phosphate to another molecule.
• In the process, ATP becomes ADP (adenosine
diphosphate) and energizes molecules.
• ADP is then re-made into ATP by dehydration synthesis.
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What is energy in biology?
ATP
Adenosine TriPhosphate
Whoa!
HOT stuff!
Murdoch
Online upload 2014
2009-2010