Membrane Structure and Function

Chapter 7

1. Why do we call the cell membrane a fluid mosaic?

2. How is membrane fluidity maintained?

3. What would you expect the membrane lipids in cold weather plants to differ from warm weather plants?

4. Briefly describe the functions of membrane proteins.

5. What is the role of the rough ER and Golgi in the formation of membranes?

6. How does a protein end up embedded in the outside of a cell membrane?

7. What factors contribute to the selective permeability of the cell membrane?

8. How does the random movement of molecules bring about an even distribution of molecules throughout the system?

9. Define the terms hypotonic, hypertonic and isotonic and explain what would happen to both a plant cell and an animal cell if it were placed in each of these solutions.

10. What is facilitated diffusion?

11. Why do cells sometimes need active transport?

12. How can a concentration gradient across a membrane be a source of potential energy?

13. Explain how the sodium-potassium pump generates a membrane potential or electrochemical gradient.

14. Describe cotransport and explain how it is useful to cells?