CELL%20TRANSPORT

1
CELL TRANSPORT

• Cell membrane is semipermeable- allows certain
  things in, keeps certain things out
• Some molecules can pass right through small
  spaces in membrane DIFFUSION- high concentration
  to low concentration
• Achieves equilibrium

2
OSMOSIS

• Diffusion of water across membrane osmosis
• Cells must maintain certain concentration of
  water- water in cell creates osmotic pressure
• Concentration of molecules (salts, sugars, ions)
  outside of cell usually to inside
• Thus- water moves in at the same rate it moves out

3
Osmotic Environments

• Isotonic
• Hypotonic
• Hypertonic

4
OSMOSIS

• Isotonic- ISO- same
• Concentration of solutes is in and out of cell
• Cell maintains regular shape

5
OSMOSIS

• If concentration of solutes in the cell is
  greater than outside, then the outside is
  HYPOTONIC to the cell
• Cell will swell as water rushes in
• Think 1.) Hypo- under, or low (solution has lower
  amount of particles)
• 2.) HypOtonic
• Good for plant cells- creates turgor pressure

6
OSMOSIS

• If concentration of solutes in the cell is less
  than outside, then the outside solution is
  HYPERTONIC to the cell
• Cell will shrink because water rushes out
• Think- HYPER greater (solution has greater
  amount of particles)
• Bad for plant cells- cells become PLASMOLYZED

7
OSMOSIS

• Water always travels from the hypotonic area to
  the hypertonic area
• Hypo-------------? Hyper
• H2O