Download Cellular Communication - Sonoma Valley High School

Cell boundaries
Hydro= water
Philic= loving
Phobic= afraid of
Cell Membrane
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Regulates what enters and leaves the cell
Provides protection and support
Forms a barrier between the cell and its
surroundings
3 parts
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Lipid bilayer: a flexible sheet of 2 layers of lipid
cells
Protein channels allow large molecules to enter
the cell
Carbohydrate chains: act as identification cards
Cell wall:
plants
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Provides support, protection for the cell
Forms outside the cell membrane
allows water, gases to pass through
Made of cellulose fibers
Osmosis
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The diffusion of water
If there is more water outside the cell, water will
move in.
If there is more water inside the cell, water will
move out.
Osmosis cont’d
Hypotonic: cell has less water than the outside
Hypertonic: cell has more water than outside
Isotonic: concentrations are equal in and out
Facilitated diffusion
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Protein channels help move large molecules like
glucose into the cell
Doesn’t require energy
Active
transport
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Moves materials against the concentration
gradient
Requires energy (ATP)
Used to move sodium & potassium
Endocytosis & Exocytosis
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Pockets or infoldings of the membrane can bring
materials into or out of the cell
Endo: materials are brought into the cell
Exo: materials are released from cell via the Golgi
apparatus
Phagocytosis: “cell eating”
macrophage ingesting e. coli bacteria