Bellwork- Have slate, marker & eraser on desk 1. Draw a BEFORE picture of YOUR egg in the beaker and label where you think these 4 things were at the BEGINNING of the experiment: sugar/salt, water, cell membrane and cell 2. Draw an AFTER picture of YOUR egg in the beaker and label where you think these 4 things were at the END of the experiment: the sugar/salt, water, cell membrane, and cell 3. When finished  complete your textbook notes for 3.5 (sections: inside & outside, diffusion, osmosis) OR review the textbook notes if already finished TIME IS 1:48

Textbook Time Set up paper for textbook notes on these sections of 3.5 today: Inside & Outside Diffusion Osmosis 3.5 Cells and Their Environment Textbook Notes Vocabulary: (not today) 7. (not today) Inside and Outside-Be prepared to stop: (sentence summaries- 1 sentence summary for each paragraph) Finished early? Begin graphing solute/ conc vs change in weight for egg lab IV=X-axis, DV=y-axis

What would be different about skateboarding UP this hill rather than DOWN it?

Cell Membrane & Transport Notes

Passive Transport Passive transport – Solute passes through membrane – NO energy required (like skateboarding DOWN a hill) – Only SMALL, uncharged molecules Do you see WHERE in the membrane the small molecules would slip through?

Active Transport – Solute passes through membrane – ATP energy required (like going UP a hill) – Moves large & charged molecules Do you see WHERE in the membrane the large/charged molecules would get moved through?

Which kind of transport happened during the egg lab? Use the definitions to explain WHY.

Passive Transport Passive transport – A solute passes through the cell membrane – NO energy required (like skateboarding DOWN a hill) – Only SMALL, uncharged molecules can do this (salt breaks apart into Na+ and Cl- ions, and sugar is a large macromolecule)

If the salt and sugar could not pass the membrane…WHAT DID MOVE? How did the eggs change weight?

Osmosis!!! water Movement of water across a semi-permeable membrane: Water moves from LOW  HIGH concentration areas Memory strategy: “Water follows the salt”

Draw a picture showing the concentrations inside vs outside the egg if it GAINED weight What does this mean about the salt & sugar concentrations INSIDE of the egg if “water follows the salt”?

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

Closure Use osmosis to explain why your fingers get wrinkly when you’re in a pool for too long.