Biology 1
Lab Report Outline
Title: Diffusion and Osmosis - Passive Movement of Molecules in Biological Systems
Introduction:
Write a summary in your own words describing the principles of osmosis and diffusion. Be sure to
describe Brownian movement, diffusion, differentially permeable membranes and what molecules can
and can't cross such a membrane, dialysis and the role of dialysis tubing, osmosis, solvents, solutes,
hypotonic, hypertonic, and isotonic environments.
Materials:
For procedure 9.3 (observing diffusion) and 9.4 (observing osmosis) please list all the materials that
would be needed.
Methods:
Please describe the experimental procedure for the following two experiments: experiment demonstrating
diffusion (procedure 9.3) and for the experiment demonstrating osmosis (procedure 9.4)
Results/Data:
Record where a color change was seen for the starch/iodine diffusion test.
Record where a color change was seen for the sodium hydroxide(NaOH)/phenolphthalin test.
Fill in data in table 9.1
0 min 15 Minutes 30 minutes 45 minutes 60 Minutes
Initial
weight
Total
weight
Change
in weight
Total
weight
Change
in weight
Total
weight
Change
in weight
Total
weight
Change in
weight
Bag A
Bag B
Bag C
Bag D
Conclusion:
1. For procedure 9.3 describe what the color change was and where it was seen (in the bag and/or the
beaker).
2. Based on the color change seen which molecule/ion moved across the membrane for the two test
referenced in question #1.
3. Answer Question 5a, 5b, 5c, 5d under procedure 9.5 the Osmosis test.
