Objectives:

1. Objectives: • Today we will… • Osmosis & Diffusion Lab • So that we can… • Define Osmosis, Diffusion, Hypertonic, Hypotonic, Isotonic, semi-permeable • Predict how water and other substances will flow across the cell membrane

2. Bellwork Brainstorm: Please try to explain this diagram to your partner.

3. The Cell Membrane – A Closer Look: What is the cell membrane made of? What is it’s function?

4. Cell Membrane – A Closer Look: The processes in which materials pass through the cell membrane are called OSMOSIS and DIFFUSION. Ccell membrane

5. Osmosis & Diffusion: Please scan the first page of today’s lab. Highlight the definitions of: • Selectively Permeable Membrane • Diffusion • Dynamic Equilibrium • Osmosis

6. Selectively Permeable Membrane: How is the bunny’s cage “selectively permeable?” http://www.buzzfeed.com/briantron/funny-bunny?sub=3465949_3949433&utm_term=30neby3#ewgs8w

7. Lab: Please answer questions 1a and 1b on the first page of your lab now.

8. Osmosis & Diffusion: Describe what happens to the food coloring in the water. Which process does this demonstrate?

9. Lab: Please answer question 2a on the first page of your lab now.

10. Diffusion: The movement of particles from an area of higher concentration to an area of lower concentration . Ccell membrane

11. Diffusion: Diffusion continues until “dynamic equilibrium” is reached. Where in the diagram to you see dynamic equilibrium? Ccell membrane

12. Practice with Diffusion:

13. Osmosis & Diffusion: • In what ways is osmosis SIMILAR to diffusion? • In what ways is it DIFFERENT?

14. Cell Membrane – A Closer Look: • Osmosis = movement of water across a membrane to dilute more concentrated areas

15. Practice with Osmosis:

16. Why are osmosis & diffusion important for cells?

17. Lab: Testable Question: How does the size of a molecule affect its ability to diffuse across a selectively permeable membrane?

18. Safety: Goggles are required for the full lab time because: • Glass can break. • Iodine is a irritant. Aprons are optional: • Iodine will stain clothes.

19. Follow the directions on the O & D lab carefully. Be precise in your measurements and weights. • Please keep your box, desk space, and community area clean. • When finished, please put all components back in the table box, clean and organize for the next class.

20. While you wait… • Design your follow up investigation (Page 5) • Complete the osmosis & diffusion practice problems (Page 6) • Honors: Complete the honors extension (Page 7 & 8)

21. Clean Up: • Glucose strips and dialysis tubing can go in the trash. (Do NOT throw away the green clips!!!) • Your beaker, green clips, and plastic spoon need to be rinsed and returned to the bucket. • Wash your hands – iodine is a skin irritant.

22. Homework: • WS to prep for Friday quiz • Organelles • Types of Cells • Typed O & D Rough Draft Conclusion due Monday for peer editing. Final O & D copy due Tuesday.

23. Lab Make Up Option: • https://www.youtube.com/watch?v=hxZFU2LBfgA • Or search for “Diffusion Demo Bozeman Science” • 7:17 minutes long