Download Chapter 7 Questions What criteria of a substance determines if it will

Chapter 7 Questions
1.
What criteria of a substance determines if it will be able to pass through the
phospholipid bilayer. Give two examples of substances that can move through the
bilayer and two examples of substances that can’t.
2. Explain the Fluid Mosaic model of the cell membrane and describe the functions of the
proteins that are embedded in the membrane.
3. How is it possible that a protein can be embedded in the plasma membrane and also
have regions that are attracted to the intracellular and extracellular regions of a cell?
4. Diagram the cell membrane. Label the following parts: lipid bilayer, integral proteins,
peripheral proteins, cholesterol, cytoskeleton, extracellular matrix, glycoproteins,
glycolipids. Explain the function of each part of the cell membrane in contributing to the
functioning of the cell.
5. If cells can not visually inspect other cells, how do the cells of our immune system
know if a particular cell they encounter is part of us or part of another organism?
6. Compare and contrast the cell wall and the extracellular matrix. Provide at least one
similarity and one difference.
7. Make a table comparing and contrasting tight junctions, gap junctions, desmosomes and
plasmodesmata. Include the type of cells they are found in, their structures, functions and
if they are open for material transport or closed.
8. How does the second law of thermodynamics allow for diffusion of substances?
9. Explain the major difference between simple diffusion and facilitated diffusion.
10. How is active transport possible, since it contradicts the tendencies of the second law of
thermodynamics?
11. Where does the energy to power active transport come from?
12. Diagram one complete cycle of the Sodium-Potassium pump. Is this active or passive
transport?
13. What is osmosis? What is tonicity?
14. Explain the meaning of the statement: “Tonicity is only useful as a comparative term.”
15. Is it possible for a solution to be both hypertonic and hypotonic? Why or Why not?
16. Why do animal cells prefer to be in isotonic solutions, while plant cells prefer to be in
hypotonic solutions?
17. How does a paramecium deal with its hypotonic environment?
18. How do large molecules get taken into the cell?