Download Cellular Respiration

Cell Energy:
Photosynthesis & Respiration
Chapter 3:2
Chapter 7:1
How Does a Plant Make It’s Own
Food?
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Plants use carbon dioxide (CO2),
water (H2O), and sun’s energy to
make food.
This is called “photosynthesis”
The food gives plants energy
Animals get the energy stored in
plants when they eat them.
Why it matters: Understanding
how plants & animals get energy
to grow & develop is an
important part of biology.
How Do Plants Get Energy From Sun?
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Plants have pigments that
absorb energy from light
Chlorophyll (found in
chloroplasts) is the pigment
used in photosynthesis
What “Food” do Plants Make?
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The “food” plants
make is a sugar
called glucose
(C6H12O6).
Glucose and oxygen
(O2) are made during
photosynthesis.
How Do Organisms Get Energy
From Food?
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Animals cannot make their own food like plants can.
But, BOTH plants and animals must break down
(digest) food in order to get energy from it (so they
can live, grow, & develop)
Cells do this 2 ways: cellular respiration and
fermentation
Cellular Respiration & Fermentation
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Cellular Respiration uses oxygen (O2) to break down food
Fermentation does not use oxygen
Cellular respiration releases more energy from food than
fermentation.
So most eukaryotes
(ex: plants & animals)
get their energy through
cellular respiration
Cellular Respiration
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Cellular Respiration =
chemical process that
happens in cells and
produces (ATP
energy)
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In eukaryotes, it
happens mostly in the
mitochondria
Process of Cellular Respiration
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Food (glucose) is broken down into CO2 and H2O and
energy is released
C6H12O6 + 6 O2  6 CO2 + 6 H2O + energy (ATP)
This energy can be used for:
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Keeping a constant body temperature
Storage (ATP) - to be used later for things like growth
What Do You Notice?
Check It Out!
Did you notice that cellular respiration is just the opposite of
photosynthesis?
 Photosynthesis:
sunlight
6CO2
+
carbon dioxide
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Respiration:
6H2O ----------> C6H12O6 +
water
chlorophyll
glucose
6O2
oxygen
Equation Facts:
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Word equations – are written with words
Chemical equations – are written with chemical symbols
You read the arrows as yields (or equals)
The words above and below the arrows are USED BUT
UNCHANGED
The substances on the left side of the arrow are called
reactants (or raw materials) of the chemical reaction
The substances on the right side of the arrow are called
products of the chemical reaction (they are what is made)
Know the substances by their word and their chemical
symbols
We get the carbon dioxide and oxygen cycle from these two processes!
CARBON DIOXIDE AND OXYGEN CYCLE
Fermentation
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Happens when cells cannot
get the oxygen they need for
cellular respiration
Fermentation is a way to get
energy when oxygen isn’t
available
Yeast is an example of
fermentation
This type of energy is less
than what you get during
respiration
Ex: During fast races you
might get a burning feeling
in you leg muscles because of
a build up of lactic acid (made
during fermentation)
Today’s Learning Goals
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In plants, chloroplasts capture
energy from the sun in order
to make food during
photosynthesis
Cells release energy from food
through either cellular
respiration of fermentation
Why it matters: Understanding
how plants & animals get
energy to grow & develop is an
important part of biology.