Osmosis

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

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”

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

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.

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