Cell Boundaries and Movement

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Cell Boundaries and Movement
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Cell Barriers

• Cell membranes
• Structure contain a flexible lipid bilayer with
  imbedded protein molecules and carbohydrate
  molecules
• Function Substances move across the cell
  membrane through
• A.) lipid bilayer
• B.) protein channels
• C.) assistance of protein
• molecules
• D.) Processes of endocytosis
• and exocytosis

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Cell Barriers

• Cell Walls
• Structure made mostly of tough carbohydrate
  fiber called cellulose
• Function Cell walls support and protect cells
  cell walls are porous and allows substances to
  move through easily

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Types of Movement Through Cells

• A.) Diffusion
• B.) OSMOSIS
• C.) Facilitated Diffusion
• D.) Active Transport

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REMEMBER DIFFUSION?
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WATER IS SO SPECIAL. WHEN IT DIFFUSES ACROSS A
SEMI-PERMEABLE MEMBRANE. IT HAS A SPECIAL
NAME OSMOSIS
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REMEMBER

• WHICH WAY DO SOLUTES WANT TO MOVE?
• FROM ______________ concentration to
  ______________ concentration.

THE SAME CAN BE SAID ABOUT WATER.
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Osmosis

• The diffusion of water across a cell membrane
• Types of osmotic solutions
• Hypotonic
• Isotonic
• Hypertonic

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Which way will the water move?
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Whats up with these blood cells?
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3 Types of Solutions
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Hypotonic Solution
Animal Cell
Lower solute concentration outside cell

• the solution has a lower solute concentration
  than the cell so water moves into the cell
  causing plant cells to swell and animal cells to
  swell and burst

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Isotonic Solution
Animal Cell

• The concentration of solutes is equal inside and
  outside the cell so water moves across the
  membrane in both directions maintaining cell size

Equal solute concentration inside and outside
cell
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Hypertonic Solution
Animal Cell

• The solution has a higher solute concentration
  than the cell so water moves out of the cell and
  into the solution causing the cell to shrivel.

higher solute concentration outside cell
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Time for your brain to hurt.
1 2 3
WHAT SOLUTION ARE TUBES 1, 2, 3
in? ISOTONIC, HYPERTONIC, HYPOTONIC?
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PLANT CELLS
HYPERTONIC ISOTONIC
HYPOTONIC