OSMOSIS IS... The movement of water by diffusion across a membrane

OSMOSIS IS... “Passive” - meaning that the cell does not have to use energy to have osmosis happen Before moving on, ask yourself, “Self, can I justify which graphic best illustrates passive transport?”

OSMOSIS DEPENDS ON... … the amount of solutes in solutions in relation to each other A solution with higher solute concentration and a lower water concentration is HYPERTONIC A solution with lower solute concentration and a higher water concentration is HYPOTONIC When two solutions have the same solute concentration, they are ISOTONIC

HYPOTONIC to a HYPERTONIC Water moves from a HYPOTONIC to a HYPERTONIC solution

HYPOTONIC The cell has a higher solute concentration than the solution. So, the solution is HYPOTONIC and the cell is hypertonic. Since water moves from hypotonic to hypertonic solutions NET water movement will be into the cell and the cell will swell. If too much water moves into the cell, it will burst.

ISOTONIC The cell has the same solute concentration as the solution. So, the cell and the solution are ISOTONIC. There will be no NET water movement and the cell will remain the same size.

HYPERTONIC The cell has a lower solute concentration than the solution. So, the solution is HYPERTONIC and the cell is hypotonic. Since water moves from hypotonic to hypertonic solutions NET water movement will be out of the cell and the cell will shrink. If too much water leaves the cell, it will die.

For tomorrow... Be prepared to explain one of the following: Why organs must be stored in an isotonic solution when being transported for transplant surgery. Why IV lines given at hospitals must be an isotonic solution to the blood. Why a person needs to use a contact lens solution and not just water when storing and cleaning contact lenses. Why salt put on roads during winter storms will kill the plants along the roadway. Why salting a slug is probably the most unethical way for a slug to die. Why your fingers will prune (swell) after a bath or swim.

OSMOSIS Add a caption for the graphic. Include the following words: Color your notes if you want to clearly show solute and water in the graphic Add a caption for the graphic. Include the following words: energy time water solute hypertonic hypotonic isotonic