Download 6.5 Mitochondria and Chloroplasts

Dr. Laurie Solis
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Organisms transform
the energy they acquire
from their surroundings.
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Animals and plants are
made up of eukaryotic
cells
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In eukaryotic cells
Mitochondria and
chloroplasts are the
organelles that convert
energy to forms that
cells use for work
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Mitochondria is found in nearly all eukaryotic
cells:
Plants
Animals
Fungi
Most protists
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Mitochondria is responsible for cellular
respiration, the metabolic process that
generates ATP (extracts energy from sugar,
fats, and other fuels with the help of oxygen)
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Rarely, some cells have a single large
mitochondrian
Mostly, cells have hundreds or thousands of
mitochondria
The number correlates with the level of
metabolic activity (cells that are more active
have more mitochondria)
Two membranes:
Outer: smooth
Inner: membranes called
cristae, divides the
mitochondria into the matrix
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Found in plants and algae
Location of the process of
photosynthesis
Converts solar energy to
chemical energy by
absorbing sunlight and using
it to drive the synthesis of
organic compounds such as
sugars, from carbon dioxide
and water
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Photosynthesis takes
place in two areas of the
chloroplasts.
 grana – also called:
thylakoids
 stroma
grana (thylakoids)
chloroplast
Granum:
thylakoids stacked
like poker chips
stroma
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Specialized compartment in a cell bound by a
single membrane
Has enzymes that transfer hydrogen to
oxygen, producing hydrogen peroxide
(H2O2)
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Peroxisomes can also break down fatty acids
Detoxify alcohol in the liver
H2O2 is toxic, but peroxisomes also contain
an enzyme that converts H2O2 to H2O
Is able to do this because it is
compartmentalized.
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Plant seeds have a special kind of
peroxisome: called glyoxysomes
Stores in fatty tissue
Have enzymes that convert fatty
acids to sugar
Sugar is then used as a source of
energy
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Peroxisomes are not part of
the endomembrane system
How do they grow?
 Using proteins
 Lipids from the ER
 Lipids synthesized in the
peroxisome
 If it gets too large, it splits in
two!