Download Cell Membrane Structure and Fluid Movement

Cell Membrane Structure and Fluid Movement
Read: 2.2 Cell Membrane Structure and then answer the following questions on loose-leaf. We will be covering the
answers to questions 1 to 10 tomorrow and 11 to 20 the class after next. Be ready to share your answers with the class.
1. List the functions of the cell membrane.
2. What is the difference between a cell membrane and a cell wall…I thought that they were the same thing!
3. What does the cell membrane require a fluid consistency? Identify the component(s) that make it have a fluid
consistency.
4. Why does your body make cholesterol even if you do not eat any foods that contain cholesterol? How is
cholesterol important to the cell membrane?
5. Explain why the electron microscope is better than the light microscope at looking at the cell membrane.
6. List three other names for the cell membrane.
7. Define diffusion and include a sketch or example.
8. Explain the concept of a concentration gradient, and use a diagram to help clarify your explanation (you can use
the ski hill example if you wish).
9. Identify three different molecules that pass through the cell membrane via diffusion.
10. What is the difference between osmosis and diffusion?
11. What is homeostasis? Why is homeostasis important to cells? What can
ultimately happen if homeostasis is disrupted?
12. Diffusion allows for the effective movement of substances over short
distances. How is this important for the cell?
13. Some potato cells are immersed in tap water. Make diagrams showing the relative concentration of water in
both cells and in the water.
14. Describe the movement of water inside a cell in a hypertonic environment. How does this compare with water
movement in an isotonic and hypotonic environment?
15. How is “facilitated diffusion” different from “diffusion”?
16. Identify two situations where cells need to use active transport. Describe an additional possible situation where
active transport might make sense.
17. What would happen to a cell if its cell membrane were permeable rather than semi-permeable?
18. Why does oxygen continue to diffuse into cells on an ongoing basis? (think about the party example)
19. Explain why water pollution has such a profound effect on living organisms.
20. What is a channel protein? Why are channel proteins important to cells?