Introducing Cell Transport

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Introducing Cell Transport
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Cell Transport

• Concentration Gradient
• Concentration The amount of solute in a
  solution
• Gradient A measure of how much something
  changes when you move from one region to another.
• Put em together and what do you get?
• Concentration Gradient - measurement of how the
  concentration of something changes from one place
  to another.

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Passive Transport

• Passive Transport Molecules moving from an area
  of high concentration to low concentration.
• No energy needed

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Diffusion

• The process by which molecules spread from areas
  of high concentration, to areas of low
  concentration.
• Equilibrium Concentration is equal throughout
  solution.
• Diffusion Animation

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Osmosis

• The movement of water molecules from high
  concentration to low concentration

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Osmosis

• Hypertonic Water diffuses out of cell
• (Cell Shrinks)
• Hypotonic Water diffuses into cell
• (Cell swells)
• Isotonic Equal rate of water diffusion into and
  out of the cell
• (Cell Stays the Same)

• http//staff.jccc.net/aalarabi/memb_related_mov.ht
  m

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Facilitated Diffusion

• A form of diffusion facilitated by transport
  Proteins also known as carrier proteins

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Facilitated Diffusion

• http//highered.mcgraw-hill.com/sites/0072495855/s
  tudent_view0/chapter2/animation__how_facilitated_d
  iffusion_works.html

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Active Transport

• Active Transport The Transport of a substance
  across the cell membrane against its gradient
• Requires Energy ( usually ATP)

• http//staff.jccc.net/aalarabi/memb_related_mov.ht
  m

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Sodium/Potassium Pump
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Bulk Transport

• Endocytosis- The movement of a substance into a
  cell by a vesicle
• Cell membrane forms pouch around substance and
  then pinches off

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Bulk Transport

• Exocytosis- The movement of substance by a
  vesicle to the outside of a cell
• Vesicles fuse with cell membrane

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Cells Must Be Small

• All substances that enter or leave the cell must
  cross that cells surface
• Small cells can exchange substances better than
  large cells
• They dont have to travel as far to reach the
  center

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Cell Size Surface Area To volume