1. Block Day- February 9 Homework: Cell Transport quiz/test on Tuesday.
Finish Diffusion/Osmosis-Part2- due on Friday
Today’s plan:
Logbook check- Surprise!!
Finish Osmosis computer demo/notes
More vocabulary for Cell Transport and some practice
Checkup on Osmosis at the end of the period

2. Logbook Check Complete on a piece of scrap paper.
½ sheet will be enough
Turn over on desk when finished

3. What does semipermeable mean when talking about a membrane?
Open to entry- Diffusion and Osmosis Notes
- Turn to back of page
What does semipermeable mean when talking about a membrane?

4. Corn syrup (Karo light)
Water
Egg whites
How was the egg membrane “Semipermeable”?
Syrup could not cross the membrane, only water could cross.

5. Membrane is permeable to iodine, not starch Predict the results:
Iodine will move across the membrane into the tubing.
STARCH
IODINE

6. Iodine will cross the membrane and move into the starch solution
Predict the results:
Iodine will cross the membrane and move into the starch solution
IODINE
STARCH

7. Osmosis Simulations

8. Conclusion Solute cannot cross the semipermeable membrane.
Water is attracted to solute and gets stuck on the higher solute concentrated side.

9. Osmosis Definition
The movement of water to the higher solute concentration across a membrane

10. Make an entry-
Entry5: Diffusion and Osmosis-Part 2 - 2/9/12 See attached

11. Diffusion and Osmosis
Diffusion- The movement of particles from an area of higher concentration to an area of lower concentration, caused by the random motion of particles.
Osmosis- The diffusion of water across a semi-permeable membrane towards the side with higher solute concentration.

12. EXPLAIN Osmosis Two factors cause osmosis:
A semipermeable membrane allows water molecules to move back and forth through the membrane, but not solute molecules
Water molecules “stick” temporarily to any dissolved solute molecules.
As a result, water molecules spend more time and accumulate on the side of the membrane with the higher concentration of dissolved solutes.

13. Solutions Solute- the substance dissolved in a solution
Solvent- the substance in which a solute is dissolved
Example
In a solution of salt dissolved in water:
Salt is the solute; water is the solvent

14. Types of Solutions
hypertonic solution- a solution with a higher solute concentration than what it is compared with. (more concentrated)
hypotonic solution- a solution with a lower solute concentration than what it is compared with. (less concentrated)
isotonic solution a solution with an equal solute concentration to what it is compared with. (equally concentrated)

15. Visual examples
Liquid is LESS concentrated (HYPOTONIC) than the cell.
Cell is MORE concentrated (HYPERTONIC) than the liquid.
Liquid is MORE concentrated (HYPERTONIC) than the cell.
Cell is LESS concentrated (HYPOTONIC) than the liquid.
This was drawn on board.
Reinforced with flasks with food coloring. Comparing two flasks and class labeling hypo-, hyper-, or iso-.
The liquid and the cell are EQUALLY concentrated (ISOTONIC).

16. Complete for homework rest of worksheet
Does the water move by osmosis towards the hypertonic or hypotonic side of a semipermeable membrane?
Explain why osmosis occurs.
If a cell is placed in hypertonic solution, will it shrink, swell, or stay the same size?
If a cell is placed in hypotonic solution, will it shrink, swell, or stay the same size?

17. WHY DO YOU THINK THE EGG IN SYRUP LOST MASS?
WHY DID THE EGG IN WATER GAIN MASS?
WHY DID THE EGG IN EGG WHITES STAY THE SAME?
HOW DID THINGS/MATERIAL GET IN OR OUT OF THE CELL?
DID IT TAKE ENERGY TO MOVE IN OR OUT? WHY DO YOU THINK SO?
THE EGG IN EGG WHITES—MATERIALS MOVING IN AND OUT OR DIDN’T MOVE AT ALL?

18. Salmon are born in fresh water (lakes or streams)
Salmon are born in fresh water (lakes or streams). After 1-2 years in fresh water, salmon move to the ocean, where they do the majority of their growing. Their body fluids have approximately 1/3 the amount of solutes as the surrounding water.
When living in saltwater, the salmon is ________________
(hypertonic/hypotonic/isotonic)
The surrounding water is ___________
Will more water move into the fish or
out of the fish?