Experiment 2: Osmosis – Direction and Concentration Gradients
Data Tables and Post-Lab Assessment
Table 3: Sucrose Concentration vs. Tubing Permeability
Table 3: Sucrose Concentration vs. Tubing Permeability
Band Color
% Sucrose in Beaker
% Sucrose in Bag
Initial Volume (mL)
Final Volume (mL)
Net Displacement (mL)
Yellow
3%
30%
10
15.8
Red
3%
15%
10
12
Blue
3%
3%
10
9.6
Green
30%
3%
10
6
Hypothesis:
Take a picture of your results. Include a note with your name and date on anindex card in the picture. Insert picture here:
Post-Lab Questions
1. For each of the tubing pieces, identify whether the solution inside was hypotonic, hypertonic, or isotonic in comparison to the beaker solution in which it was placed.
2. Which tubing increased the most in volume? Explain why this happened.
3. What do the results of this experiment this tell you about the relative tonicity between the contents of the tubing and the solution in the beaker?
4. What would happen if the tubing with the yellow band was placed in a beaker of distilled water?
5. How are excess salts that accumulate in cells transferred to the blood stream so they can be removed from the body? Be sure to explain how this process works in terms of tonicity.
6. If you wanted water to flow out of a tubing piece filled with a 50% solution, what would the minimum concentration of the beaker solution need to be? Explain your answer using scientific evidence.
7. How is this experiment similar to the way a cell membrane works in the body? How is it different? Be specific in your response.
