The selectively Permeable Membrane Model the cell processes of diffusion and osmosis and relate this motion to the motion of particles.

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The selectively Permeable MembraneModel the
cell processes of diffusion and osmosis and
relate this motion to the motion of particles.
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Selectively Permeable Membrane
to choose
to pass through
thin outer boundary
A ?
B ?
Gate keeper for friendly folks but not enemies
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Membrane is permeable to
Membrane is NOT permeable to
H2O
NaCl2
O2
Macromolecules (potassium, Calcium, sodium)
CO2
Then how do these important substances move in
and out of the cell membrane?
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They move in out of the membrane by one of
these ways

• 1-diffusion
• passive transport
• 2- osmosis
• 3- transport protein
• active transport
• 4- engulfing

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What is Diffusion?

• Molecules tend to move from an area of higher
  concentration to an area of lower concentration.

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How do these paramecium get the oxygen they need
to survive from the water around them?
More oxygen in water than inside their cell so it
diffuses from high to low concentration.
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What is OSMOSIS?
-diffusion of water molecules through a
selectively permeable membrane
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Diffusion and Osmosis are considered Passive
Transport.
H2O O2 CO2
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Passive Transport-no energy needed, just
equilibrium.
Diffusion Osmosis
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If Passive transport doesnt use energy then what
about Active transport?
NaCl2 Calcium Potassium Sodium
Transport protein
Bigger molecules need energy to get in
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What do you think this cool Active transport is
called?
ENGULFING !!!
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Match these

• 1. Permeable A. Thin outer
  boundary
• 2. Osmosis B. Spreading out of
  particles
• 3. Membrane C. To choose
• 4. Diffusion D. Amoeba seeking food
• 5. Active Transport E. No energy needed
• 6. Selectively F. To pass
  through
• 7. Passive Transport G. Revolving door using
  energy
• 8. Transport Protein H. Water moving across a
  membrane
• 9. Engulfing I. Energy needed to scooter
  uphill