Movement Across the Plasma Membrane

1
Movement Across the Plasma Membrane

• Diffusion

• Movement of a substance from areas of high
  concentration to low concentration

• Does not require energy

2
Osmosis

• Diffusion across a membrane
• Still moving from high concentration to low
  concentration
• Water Concentrations

3
(No Transcript)
4
Facilitated Diffusion

• Diffusion assisted by carrier proteins
• Still follows the concentration gradient
• Moves from areas of high concentration to low
  concentration
• Does not require energy
• For substances that don't dissolve in lipid
  bilayer
• Recognized by carrier proteins and then pass
  through membrane

5
Facilitated Diffusion
6
Hydrophilic/Hydrophobic

• Hydrophobic
• Water-hating
• Low water solubility

• Hydrophilic
• Water-loving
• Dissolve readily in water

7
Concentration Jargon

• Hypertonic
• Means the solution has a higher concentration of
  solute than the cell or solution it's being
  compared to
• Saltwater would be hypertonic to tap water

• Hypotonic
• The solution has a lower concentration of solute
  than that to which it is being compared
• Tap water would be hypotonic to tap water

8
(No Transcript)
9
Active Transport

• Movement against a concentration gradient
• From areas of low concentration to high
  concentration
• Requires energy to be expended
• This energy is the molecule ATP

10
Active Transport

• Click to Start

11
Bulk Transport

• Endocytosis-
• Part of the plasma membrane encloses material and
  pinches off to form a vesicle

• Phagocytosis-
• Transported particle is food

• Exocytosis-
• The reverse vesicles formed within cells fuse
  with membrane and contents are expelled