1. Osmosis

2. Passive Transport Review
Energy requirements?
No energy required
Modes of passive transport?
Diffusion through cell membrane
The movement of a substance from higher concentration to lower concentration
Facilitated Diffusion
Diffusion through the cell membrane via a channel protein
If passive transport requires NO ENERGY, how do you think active transport differs??
Active transport requires energy in order to cross the membrane

3. Osmosis A mode of diffusion
Osmosis: the movement of water from a higher concentration to a lower concentration
“The Diffusion of water through a semi-permeable membrane”

4. Results of Osmosis
Isotonic Solution- The water and solute concentration are in equal concentrations on the inside and outside of the cell
Equilibrium has been reached

5. Results of Osmosis
2. Hypotonic Solution- The concentration of solute outside the cell is “less than” the concentration of solute inside the cell
So, there is more water outside the cell
Water moves into the cell
This causes the cell to expand, and perhaps, burst.

6. Results of Osmosis
3. Hypertonic Solution- The solute concentration outside the cell is “higher than” the solute concentration inside the cell
Water concentration is greater inside the cell
Water moves out of the cell
Cell will shrivel, shrinking in size