Bellwork- HAVE SLATE ON DESK!1. How is the cell membrane like a screened in porch or

window?2. How is it not like a screened in porch?3. Copy the picture below. If the solute is a LARGE or

CHARGED molecule, what is the ONLY thing that can pass the cell membrane?

4. What is osmosis?5. Draw arrows on a circle showing which direction(s) water

would move (in the pic below).

Announcements12 days until science fair data due

1. Notes

2. Labs

3. Assignments

4. Tests

-3.5 Outline-Cell Membrane & Transport Notes

Cell Membrane Unit Essential Question

How do our cells maintain equilibrium (balance) in a constantly changing environment?

___________________________________________________________________________________________________-Egg Lab graph & conclusion

Cell Membrane & Transport Notes

0% salt

25% sugar

What does osmosis tell us about the salt & sugar concentrations INSIDE of the egg if “water follows

the salt”?

50% salt

Does this make sense? Think about what an egg is…

Names for concentrations:

Isotonic• Iso= same• Same concentration outside the cell as inside

Hypertonic• Hyper= more/too much• Higher concentration solution outside the cell

Hypotonic• Hypo= less/too little• Lower concentration solution outside the cell

This duck egg GAINED weight in a 15% sugar solution

• Which direction must water have moved?• Where is the higher concentration of solute (think about which

direction water moves during osmosis)?• Is the 15% sugar solution iso-, hyper-, or hypo- tonic?• What % concentration is the sugar inside of the egg?• Why couldn’t the sugar have moved?

This duck egg LOST weight in a 75% sugar solution

• Which direction must water have moved?• Where is the higher concentration of solute (think about which

direction water moves during osmosis)?• Is the 75% sugar solution iso-, hyper-, or hypo- tonic?• What % concentration is the sugar inside of the egg?• Why is water able to move passively across membranes?

1. Finish graphing solute/concentration vs change in weight

Answer the 6 lab Qs AND include the following:-Use correct vocabulary (from notes, textbook) throughout to describe the results

-Cite the textbook 1-3 times in support of your claims

2. Complete conclusion (1 P) on back of graph paper

When finished- turn in graph & conclusion to front basket & pick up article on osmosis

misconceptions

Bio 1-2