Ch. 7: Membrane Structure and Function - Review

Important Vocabulary: Amphipathic, Semi-permeable, Crenation, Turgid, Lysis, Plasmolysis

Review Questions:

1. Describe the fluid-mosaic model of membrane structure.

2. Identify the following general structural components of the plasma membrane:

   1. phospholipids

   2. membrane proteins

   3. glycolipids / glycoproteins

   4. cholesterol

3. Show/recognize the molecular structure of phospholipids.

4. Explain how the amphipathic nature of molecules (with hydrophilic and hydrophobic regions) form membranes.

5. Explain the role of saturated and unsaturated fatty acids in maintaining optimum membrane fluidity.

6. Explain the role of cholesterol in membranes in maintaining optimum membrane fluidity.

7. Describe the amphipathic nature of integral membrane proteins.

8. Describe the structure of glycolipids and glycoproteins in the plasma membrane.

9. Describe the extracellular matrix attached to the outside of the plasma membrane in animal cells.

10. Describe the process of making new plasma membrane sections inside a cell.

11. List the major functions of the plasma membrane.

12. Relating to diffusion:

    1. Define diffusion.

    2. State which chemical substances can diffuse directly through the plasma membrane and which substances cannot.

    3. Distinguish between a concentration gradient, a charge gradient, and an electrochemical gradient.

    4. Define facilitated diffusion.

13. Define osmosis.

14. Distinguish between hypertonic, hypotonic, and isotonic aqueous solutions.

15. Be able to predict the direction of osmosis in different solutions.

16. Relate solution tonicity to crenation and lysis in animal cells and to plasmolysis in plant cells.

17. Define active transport.

18. Relating to bulk transport:

    1. Define exocytosis and describe the process involving a Golgi vesicle.

    2. Define endocytosis and distinguish between phagocytosis, pinocytosis, and receptor mediated endocytosis