J 1) What’s in the bottles (from yesterday)? - Describe (draw and write). - Why does this happen (use polar / non-polar)? 2) Membrane model: Write as many observations you can possibly see.

Considering the bubble lab: 1. Describe the soap film. 2. Describe what happened when you used: A. Dry Pencil, B. Wet Pencil, C. Wet tube with pencil, D. Wet thread-ring. 3. Which characteristics of the membrane were demonstrated? At least 3.

Demonstration: 3 beakers and food coloring… 1. Describe (draw + write): -What happens to the food coloring? -What is the difference between the beakers? 2. What could be the reason for this difference?

Membrane Function Part One: Diffusion of particles across the membrane. Hydro- philic Hydro- phobic Water

Solvent: Fluid Substance that is present in large amount (water, oil) Solute: Substance that is in small amount and mixed into the solvent. (food coloring, paint, sugar..) Solution: Solute mixed into solvent Concentration: Amount of solute in unit volume of solvent.

Diffusion and Osmosis Diffusion Particles move randomly as fast as the temperature allows. Concentration: Amount of particles per unit volume Solvent (water) Solute (sugar, salt, etc) Notes Diffusion Simulation Solution Diffusion Simulation, Circles, Temperature

Particles move from high to low concentrations Diffusion Simulation Spreading of a gaseous smell Spread of sugar in tea without mixing Spreading of polluting smoke Diffusion Open Memb Example: (Particles move down the concentration gradient). Notes Diffusion Animation Stolaf

Two eggs two solutions: The eggs you are looking at were de-shelled with vinegar. They were then dipped overnight – one in syrup and one in water. 1.Draw what you see. Describe. 2.Where to did the water move? 3.Which egg was dipped in syrup/water? How can you tell?

We divide all the particles to four major groups: Uncharged Polar Charged (“super-polar”) +- Large (proteins) Non-polar (lipids) Pass freely: H2OH2O Ions Na + Cl - Need help to pass:

Biological membranes are semi-permeable Pass easily: -Small molecules -Non-charged particles -WATER! Pass only with help: -Large particles -Ions ? Notes + -

Osmosis Osmosis Simulation * Osmosis is the movement of water through a semi-permeable membrane. A.B. Water movement Osmosis Semipermeable Memb * Water moves (diffuses) until the concentrations are balanced. Notes Osmosis Animation - before and After salt

Handout exercise

Before the journal… Handout: All three situations are unstable. On the right side draw in the particles and the water level after time passed for diffusion/osmosis to occur.

Two eggs two solutions: The eggs you are looking at were de-shelled with vinegar. They were then dipped overnight – one in syrup and one in water. 1.Draw what you see. Describe. 2.Where to did the water move? 3.Which egg was dipped in syrup/water? How can you tell?

1) Complete the drawing on the right of the cup: Since sugar cannot pass through, the water can and will pass. But to what direction? 2) Describe in words what happened to the water, and why.

Sugar Water

Isotonic – solutions with equal concentration. When comparing two solutions to one another, we define: A.B. Osmosis Simulation Hypotonic solution has a lower solute concentration Hypertonic solution has a higher solute concentrations

In osmosis water moves from a hypo-tonic solution to a hyper-tonic solution A.B. Water movement

1)Add the new terms to the drawing of the cup. 2)Back to the egg….: Draw the egg that was dipped in syrup right after it was dipped. Label it – where was it hypo-, hyper- or iso- tonic? 3) Draw the egg after staying overnight in syrup- label hypo-, hyper-, iso- tonic.

Diffusion Simulation Diffusion Open Memb Osmosis (New) No Cup Osmosis Semipermeable Memb Osmosis Animation - before and After salt (Stolaf) Diffusion Simulation, Circles, Temperature YouTube of a clear Osmosis Animation Diffusion, Large, No cup

Hypertonic H2OH2O Egg in Syrup isotonic Hypotonic

H2OH2O Egg in Syrup isotonic

Hypotonic Hypertonic H2OH2O Egg in Water isotonic

H2OH2O Egg in Water

Writing exercise: Draw the 3 rd example from the handout. Label: Hypertonic, Isotonic, Hypotonic, semi-permeable membrane, concentration gradient. In essay format: Tell what happened in the experiment, why. Peer (neighbor) review.

1)How would you prefer to store a salad – with or without dressing? Why? 2) What happens when you add sugar to strawberries? Why does it happen? (use “Osmosis”)

And why are we learning this?? To Explain: Why can we safely store jam at room temperature. Why do marine fish die in freshwater, and visa versa? How can we desalinate sea water? Why better store salad without dressing? And more…..

Quiz

Preparing for the Dialysis Lab Dialysis – Filtration of liquids through an artificial membrane (bag). Materials that will be added: Sugar ( ), Starch ( ….) Iodine ( ) Water ( ) 1.Which will pass through the holes ? 2. How can we tell if they passed or not?

Observe the dialysis tubing from yesterday’s lab. 1) Describe (Draw, write) what you see, as detailed as possible: 2) Which materials passed through, in what direction, and how could you tell? 3) Copy the following data chart..

DATA TABLEBeforeAfter Water: Volume changes in the ‘cell’ _______________ ________________ ml Iodine staining inside the ‘cell’ (Yes/No) Iodine color outside the ‘cell’ (Yes/No) Starch outside the ‘cell’ Sugar outside the ‘cell’: (Color; Yes/No) Color: Yes/No

Kidney tutorial and animation A Youtube about the kidneys

Explain the following processes: Wilting of salads when stored in dressing Putting an animal cell in a hypo- tonic solution? –What would happen? B. Putting an animal cell in a hyper- tonic solution? What would happen? Collapse of Blood Cell Rupture of a blood cell C. Putting a plant cell in a hypo-tonic solution? What would happen?

Why are concentrated jams or juices safe to store without cooling? Or… Which of the following must you store in the refrigerator? Vinegar, jam, flour, candy, meat, diluted juice, concentrated juice,… Why?