3.3 Cell Membrane Sponge: Set up Cornell Notes on pg. 29 Topic: 3.4 Diffusion Essential Question: Explain what a concentration gradient is and what it means for a molecule to diffuse down its concentration gradient. 2.1 Atoms, Ions, and Molecules Explain what a concentration gradient is and what it means for a molecule to diffuse down its concentration gradient. 3.4 Diffusion Key Concept: Materials move across membranes because of concentration differences.

3.3 Cell Membrane P.28 Concentration Gradient Table

KEY CONCEPT Materials move across membranes because of concentration differences. 3.4 Diffusion and Osmosis

Solution: A homogenous mixture of two or more substances, which may be solids, liquids, or gases, or the combination of these. Ex: Sugar water Solute: Substance dissolved in another substance Ex: Sugar Solvent: Substance doing the dissolving (usually the substance present in the greatest amount) Ex: Water (THE BEST SOLVENT)

Which one is the Solute? Solvent? Solution? Milk Chocolate Milk Chocolate Syrup Air Nitrogen (78%) Oxygen, argon, CO 2 (22%) Solvent Solution Solute

Passive transport- the movement of molecules across a cell membrane without energy input from the cell There are two types of passive transport. 2. osmosis 1. diffusion 3.4 Diffusion and Osmosis

Dye + WaterSalt + Water Solvent Solute Solution Hypothesis: What is going to happen when…. (If….then….) Dye is added Salt is added What happened after 5 mins? Was your hypothesis right? How did these experiments demonstrate diffusion? Pg. 28

Dye + WaterSalt + Water Solvent Solute Solution Hypothesis: What is going to happen when…. (If….then….) Dye is added Salt is added What happened after 5 mins? Was your hypothesis right? How did these experiments demonstrate diffusion? Pg. 28 Fill Out

Dye + WaterSalt + Water Solvent Water Water Solute Dye Salt Solution Colored Water Salt Water Hypothesis: What is going to happen when…. (If….then….) Dye is added If I add colored dye to the water, then it will eventually change the color of the water Salt is added If I add salt to water, then it will eventually dissolve What happened after 5 mins? Was your hypothesis right? How did these experiments demonstrate diffusion? Pg. 28

Diffusion Demonstration Materials: 2 Cups, Water, Dye, Salt, Graph 1) Identify the solvent, solute, and solution for each demonstration 2) Hypothesize what is going to happen when you drop the food coloring in the water. Salt in the water? 3) Did your hypothesis match the results?

Dye + WaterSalt + Water Solvent Water Water Solute Dye Salt Solution Colored Water Salt Water Hypothesis: What is going to happen when…. (If….then….) Dye is added If I add colored dye to the water, then it will eventually change the color of the water Salt is added If I add salt to water, then it will eventually dissolve What happened after 5 mins? Was your hypothesis right? Dye spread throughout water. Yes. Salt dissolved. Yes. How did these experiments demonstrate diffusion? Pg. 28

Diffusion: is the movement of molecules in a fluid or gas from a region of higher concentration to a region of lower concentration. 3.4 Diffusion and Osmosis

Air Freshener Demo.

Diffusion: is the movement of molecules in a fluid or gas from a region of higher concentration to a region of lower concentration. 3.4 Diffusion and Osmosis

Diffusion: is the movement of molecules in a fluid or gas from a region of higher concentration to a region of lower concentration. 3.4 Diffusion and Osmosis

Diffusion Demonstration Materials: 2 Cups, Water, Dye, Salt, Graph 1) Identify the solvent, solute, and solution for each demonstration 2) Hypothesize what is going to happen when you drop the food coloring in the water. Salt in the water? 3) Did your hypothesis match the results? 4) Explain how these experiments demonstrated diffusion

Dye + WaterSalt + Water Solvent Water Water Solute Dye Salt Solution Colored Water Salt Water Hypothesis: What is going to happen when…. (If….then….) Dye is added If I add colored dye to the water, then it will eventually change the color of the water Salt is added If I add salt to water, then it will eventually dissolve What happened after 5 mins? Was your hypothesis right? Dye spread throughout water. Yes. Salt dissolved. Yes. How did these experiments demonstrate diffusion? The dye moved from an area of higher concentration to an area where less dye was The salt dissolved or moved from an area of higher concentration to an area of lower concentration Pg. 28

Concentration gradient- the difference in the concentration of a substance from one location to another. Molecules diffuse down their concentration gradient Bottom pg. 28

3.3 Cell Membrane How Diffusion Works

3.3 Cell Membrane Sponge: Set up Cornell Notes on pg. 31 Topic: 3.4 Osmosis Essential Question: A cell is bathed in fluid. However, you notice that water is flowing out of the cell. In what kind of solution is this cell immersed? 2.1 Atoms, Ions, and Molecules A cell is bathed in fluid. However, you notice that water is flowing out of the cell. In what kind of solution is this cell immersed? 3.4 Osmosis

3.3 Cell Membrane Isotonic SolutionHypertonic Solution Hypotonic Solution Pg. 30 Osmosis Pic Video Notes

Osmosis is the diffusion of water molecules across a semipermeable membrane. 3.4 Diffusion and Osmosis

The water will continue to move across the membrane until it reaches “equilibrium” or an isotonic state Draw on Pg. 30

There are three types of solutions. 3.4 Diffusion and Osmosis Same amount of solutes/water inside and outside cell = amounts of water enter and leave the cell Stays the same size!

There are three types of solutions. 3.4 Diffusion and Osmosis More solutes outside the cell than inside the cell More water inside the cell than outside the cell More water exits cell Shrinks!

There are three types of solutions. 3.4 Diffusion and Osmosis More solutes inside the cell than outside the cell More water outside cell than inside the cell More water enters cell Expands!

Osmosis Videos Osmosis vs. Diffusion Osmosis vs. Diffusion Osmosis Computer Graphics Osmosis Computer Graphics Osmosis Demo Video Osmosis Demo Video Osmosis with a U-tube Osmosis with a U-tube Osmosis in the kitchen Osmosis in the kitchen Osmosis with an Egg Osmosis with an Egg Desalination- Reverse Osmosis Desalination- Reverse Osmosis Video Notes on P. 30 (15-20 bullets/examples)

Some molecules cannot easily diffuse across the cell membrane Ex: H 2 O Facilitated diffusion is diffusion through transport proteins Things like H 2 O would be repelled by the phospholipid tails, so transport proteins allow the H 2 O to diffuse easily 3.4 Diffusion and Osmosis

GUMMI BEAR LAB- OSMOSIS

PredictionsConclusion Sugar Water Distilled Water Salt Water. Table 1: Predictions and Conclusions Gummi Bear Osmosis Lab Starting Information Weight (g) Length (mm) Width (mm)

Osmosis Lab Materials Materials: 1 cup Water Sugar 1 Gummi Bear Scale (g) Ruler (mm) String (for width) Salt 1) Label each cup: First/Last Name Period #

Day One: Gathering Data 1) Weigh your Gummi Bear and record its weight (g) 2) Measure your Gummi’s length and width (mm) 3) Place the Gummi in a 25/75 sugar/water solution 4) Fill in your table with your hypothesis

Day Two: Gathering Data 1) Dry your Gummi bear off carefully 2) Weigh your Gummi Bear and record its weight (g) 3) Measure your Gummi’s length and width (mm) 4) Was your hypothesis correct? What happened to your Gummi? Compare this data with your group data, and record on Lab report tables. 5) Rinse out your cup and rinse off your gummi (quick and carefully) 6) Place the Gummi in a 100% distilled water 7) Fill in your table with your new hypothesis

Day Three: Gathering Data 1) Dry your Gummi bear off carefully 2) Weigh your Gummi Bear and record its weight (g) 3) Measure your Gummi’s length and width (mm) 4) Was your hypothesis correct? What happened to your Gummi? Compare this data with your group data, and record on Lab report tables. 5) Rinse out your cup and rinse off your gummi (quick and carefully) 6) Place the Gummi in a 25/75 solution of salt and water 7) Fill in your table with your new hypothesis