Download Vacuoles

Vacuoles
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Membrane bound spaces with a cell
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May be small-food storage
May be quite large like the tonoblast in plant cells
Tonoplast and Central Vacuole
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Storage for many chemicals
 Ions, proteins, water
Often plays role in tissue specific role
 Pigment of flowers, toxins for defense
Can elongate to take up more or less space within cell
Fig. 6-15
Central vacuole
Cytosol
Nucleus
Central
vacuole
Cell wall
Chloroplast
5 µm
Mitochondria and Chloroplasts

Both are power providers of cell

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Chloroplasts are like solar power plants
Mitochondria are like coal-burning plants
Both are membrane-bound organelles
Both contain their own DNA which encodes
some proteins and ribosomes specific for their
activity
Both move about within cell and divide to
form more organelles.
Endosymbiant Theory

Chloroplasts and Mitochondria have evolved
directly from bacteria that were internalized
into anther prokaryotic cell
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Mitochondrial ancestor was effective at
respiration and utilizing complex chemicals
Chloroplast ancestor was photosynthetic and
able to derive energy from sunlight
Mutualistic relationship-where both partners
benefit from the interaction
Mitochondrial structure


Mitochondria is responsible for respiration
Reactions are membrane-associated
 Maximized membrane surface area
 Many proteins are bound to inner membrane
 Cristae are folds of inner membrane
 Matrix is the fluid surrounding cristae
Fig. 6-17
Intermembrane space
Outer
membrane
Free
ribosomes
in the
mitochondrial
matrix
Inner
membrane
Cristae
Matrix
0.1 µm
Chloroplasts



Have double membrane with space in between
Have additional membrane structures called thylakoids within-where
chlorophyll is stored
 Look like poker chips
Stroma surrounds thylakoids
 Interaction between stroma and thylakoids is
important
Fig. 6-18
Ribosomes
Stroma
Inner and outer
membranes
Granum
Thylakoid
1 µm