1. Membranes and Cellular Transport
WARM-UP:
Write a story about organelles, in 7 words.
Adventure vesicle reached the membranes. Golgi waved.
Adventure vesicle roamed the membranes. Golgi waved.

2. Animal cells vs. Plant cells
Both are bound by membranes and both live in fluid environments. Plant cells have a cell wall and this changes the way that the cells behave in fluid environments.

3. Objective:
Describe the function and components of biological membranes
Relate membrane function to HOMEOSTASIS.

4. Oil and Water don’t mix!

5. What will happen if you have one molecule with two different solubility behaviors?
Water Soluble
Not Water Soluble

6. Membrane lipids

7. Detergent micelles lift and solubilize dirt

8. Which biomolecule is the building block of membranes?

9. Structure of the cell membrane

10. Phospholipids alone don’t make up a living membrane

11. Anatomy of a red blood cell

12. What happens to red blood cells in capillaries (tiny blood vessels?)

13. Predict: What are the possibilities?
What happens when you put a red blood cell in water?
What happens when you put a red blood cell in salt solution?

14. Diffusion, Osmosis, Cellular Transport

15. Define the following:
1. Hypotonic
2. Hypertonic
3. Isotonic

16. Relative solute concentrations outside and inside cells
Cytosol
Outside isotonic
Solute
Cytosol
Outside isotonic
Outside hypertonic
Water
Outside hypotonic
Water 
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

17. A biologist working with cultured cells uses distilled water instead of serum. When he looks for the cells he sees only debris. What happened to his cells?
What are the possibilities?

18. What happens when we expose onion cells to high salt?
Procedure:
Place a thin sliver of moist onion tissue (red colored) onto a glass slide.
Put a drop of water on the slide and drop a cover slip. Record your observations.
Now touch the edge of the slide with a dropper filled with salt solution. Allow salty water to draw across the cover slip. Record the time and record your observations.

21. Frog Oocytes expressing putative transport protein
Control
CHIP28 protein
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

22. Oocytes placed in Hypotonic medium
Oocyte rupturing
Oocyte
Control
CHIP28
3–5 minutes
Courtesy Dr. Peter Agre. From GM Preston, TP Carroll, WP Guggino, P Agre (1992), “Appearance of water channels in Xenopus oocytes expressing red cell CHIP28 protein,” Science, 256(5055):385–7
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

23. Facilitated Diffusion
Aquaporin: protein channel that allows water to enter cells at a faster rate than diffusion
Facilitated Diffusion

24. Brain teaser:
Emma has stomach aches and persistent diarrhea. Her favorite drink is apple juice. Emma’s pediatrician wants her to cut back. What is going on?