Honors Biology Cell Membrane and Passive Transport:
1. Describe the structure and function of a cell’s plasma membrane and all the parts that make it up.
2. Explain why a cell membrane is called a fluid mosaic.
3. For each pair of terms, explain how the meanings of the terms differ.
a. diffusion and facilitated diffusion
b. hypotonic and hypertonic
c. plasmolysis and cytolysis
4. Explain the relationship between plasmolysis and turgor pressure in plant cells.
5. Use the following terms in the same sentence: carrier protein, concentration gradient, facilitated diffusion, and passive
transport .
6. Explain why diffusion eventually results in equilibrium.
7. Identify whether all molecules diffuse through all cell membranes. Explain your answer.
8. Distinguish between diffusion and osmosis.
9. Describe what it means to say that two solutions are isotonic.
10. Define the term contractile vacuole. What is a contractile vacuole’s function?
11. Determine how hypotonic, hypertonic and turgor pressure are interrelated.
12. Summarize the factors that determine the direction of net movement of water across a cell membrane.
13. Determine how the phospholipid bilayer of a membrane forms a barrier to molecules.
14. Explain how substances cross a cell membrane through facilitated diffusion.
15. Describe how ion channels assist in the diffusion of ions through a cell membrane.
16. Distinguish between passive transport and active transport
17. There is a higher concentration of air molecules inside an inflated balloon than there is outside the balloon. Because of
their constant random motion, the molecules inside press against the balloon and keep it taut. How is the pressure exerted by
these air molecules similar to turgor pressure? How is it different?
18.Sometimes, water seeps through the concrete wall of a basement after a heavy rain, and the homeowner must remove the
water with a sump pump. How can this situation be compared to the action of a unicellular nonphotosynthetic organism that
lives in a pond?
19. The drawing below shows a plant cell after the solute concentration of its environment has been changed. How would you
describe the new external environment?
Name _________________________________________________ Date ________________ Hour ______
Diffusion and Osmosis Worksheet
Below are semi-permeable bags filled with various concentrations of solutions placed in
beakers with various concentrations of solutions. Use this information to help answer the
questions below for each set-up.
• The solutions are prepared with distilled water.
• The semi-permeable membrane bag is permeable to glucose, a very small sugar
molecule.
• The semi-permeable membrane bag is NOT permeable to sucrose, a larger sugar
molecule.
For each set-up, you must:
1. Indicate whether the solution in the bag is isotonic, hypertonic, or hypotonic to the
solution in the beaker.
2. Draw a blue arrow for the net movement of water by osmosis (do not draw any arrow
if there would be no net movement of water).
3. Draw a green arrow for the net movement of solute by diffusion (do not draw any
arrow if there would be no net movement of solute).
4. Explain why you drew the arrows you did in terms of the properties of diffusion, osmosis,
and semi-permeable membranes. Be sure to include concentrations of solutions in
your explanation.
0.5 M
Sucrose
0.1 M
Sucrose
0.2 M
Glucose
0.2 M
Glucose
The solution in the bag is
______________________________________
compared to the solution in the beaker
The solution in the bag is
______________________________________
compared to the solution in the beaker
Explain your arrows:
Explain your arrows:
0.4 M
Sucrose
0.9 M
Sucrose
1M
Sucrose
0.9 M
Sucrose
The solution in the bag is
______________________________________
compared to the solution in the beaker
The solution in the bag is
______________________________________
compared to the solution in the beaker
Explain your arrows:
Explain your arrows:
1M
Glucose
0.9 M
Glucose
0.1 M
Glucose
0.7 M
Glucose
The solution in the bag is
______________________________________
compared to the solution in the beaker
The solution in the bag is
______________________________________
compared to the solution in the beaker
Explain your arrows:
Explain your arrows:
0.6 M
Sucrose
di H2O
0.6 M
Sucrose
1M
Glucose
The solution in the bag is
______________________________________
compared to the solution in the beaker
The solution in the bag is
______________________________________
compared to the solution in the beaker
Explain your arrows:
Explain your arrows:
0.8 M
Sucrose
di H2O
1M
Sucrose
2M
Sucrose
The solution in the bag is
______________________________________
compared to the solution in the beaker
The solution in the bag is
______________________________________
compared to the solution in the beaker
Explain your arrows:
Explain your arrows:
1M
Glucose
1M
Glucose
0.2 M
Glucose
0.1 M
Glucose
The solution in the bag is
______________________________________
compared to the solution in the beaker
The solution in the bag is
______________________________________
compared to the solution in the beaker
Explain your arrows:
Explain your arrows:
di H2O
.8 M
Sucrose
The solution in the bag is
______________________________________
compared to the solution in the beaker
Explain your arrows:
Using the set-up to the left, explain how
you would test your explanation. Make
sure to include what you would use to
produce quantitative data.