ATP and Chemical Energy
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Objectives
• SWBAT recognize the importance of ATP as an
energy-carrying molecule.
• SWBAT identify energy sources used by
organisms.
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Review Vocabulary
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Glucose
Carbohydrate
Monosaccharide
Polysaccharide
Starch
Cellulose
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What is this molecule?
• What is this molecule?
– C6H12O6
• Who makes it?
• Why is it important?
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Glucose is the building block
• Glucose is linked together to make all sorts of
different macromolecules (molecules that are
really big) like starch and cellulose.
These are 2 glucose
molecules joined to
make a molecule
known as table sugar
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Vocabulary
• ATP
• ADP
• Homeostasis
• Triglyceride
• Glucose
Review Vocabulary If Needed
• Carbohydrate
• Monosaccharide
• Polysaccharide
• Starch
• Cellulose
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SciShow: ATP and Cellular Respiration
• https://www.youtube.com/watch?v=00jbG_cf
GuQ
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Energy and Food
• When we need energy, we eat.
– The foods we eat are carbon-based molecules –
carbohydrates, starches, proteins, lipids, etc.
• The question then is, how does food give you
energy?
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Energy and Food
• Before energy can be extracted from food, it
has to be broken down (energy comes food
but not directly). There is no ATP in the food
you eat.
• All the carbon-based molecules in food
contain energy in their bonds.
– This energy is useable only when those bonds are
broken and the energy is released.
– Carbohydrates and lipids are the most important
energy sources in the food you eat.
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Bonds need to be broken
• Molecules in food store chemical energy in
their bonds – breaking the bonds frees energy.
Starch molecule
Glucose molecule
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ATP - Currency of Cellular Energy
• ATP transfers energy from the breakdown of food
molecules to cell functions.
– Energy is released when a phosphate group is removed.
– ADP is changed into ATP when a phosphate group is
added.
phosphate removed
Energy from breaking the
carbon and other bonds in
the food you eat.
Energy is released when a
phosphate is removed from the
ATP molecule.
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ATP - Currency of Cellular Energy
• ATP is chemical energy that is available to the
cell to power its necessary functions.
– Your cells use ATP to move materials by active
transport, exocytosis, and endocytosis.
– They also use ATP to create molecules such as
proteins, lipids, nucleic acids, and any other
molecule they need in order to function properly
(to maintain homeostasis).
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ATP - Currency of Cellular Energy
Energy is released when a
phosphate is removed from the
ATP molecule.
Biosynthesis is
the production
of complex
molecules
within living
cells.
When the phosphate is
removed and energy released,
ATP becomes ADP.
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ADP
• ADP is adenosine diphosphate.
– It is a lower-energy molecule than ATP.
– It can be converted into ATP by the addition of a
phosphate group.
This is a simplified version of the
cycle that turns ADP into ATP.
This process is not simple.
phosphate removed
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ATP/ADP
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Molecular Structure of ATP
Adenine
Nucleotide
Nucleoside
Ribose
Sugar
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Making ATP
• Digestion breaks down food into smaller
molecules (think glucose) that then can be
used to make ATP.
– Different foods have different amounts of calories,
which indirectly related with how much ATP each
type of food can make.
– Carbohydrates are the most commonly broken
down molecule to make ATP. The breakdown of
the simple sugar glucose yields about 38
molecules of ATP.
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Making ATP
• The body does not store carbohydrates (it
burns them); however, the body does store
lipids.
– Lipids store about 80% of the energy in your body
– they are our fat stores.
– When broken down, they make about 146
molecules of ATP from one triglyceride (this is
why animals pack on the fat to survive periods
when there is very little food).
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Making ATP
• Proteins are least likely to be broken down to make ATP.
– amino acids not usually needed for energy
– about the same amount of energy as a carbohydrate
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Making ATP
Polar bears will go months without
eating (stranded on land) – living on
their fat until pack ice is formed and
they can hunt seals.
This is a wild polar bear who lives on
Hudson Bay (in Manitoba). While waiting
for the ice to form, this polar bear made a
friend – a sled dog. The bear visited the
dog on several occasions to play. When
the ice formed, the bear went on his way.
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