Investigating Osmosis using water and gummy bears
In this biology classroom lab, students investigate the affect of soaking a Gummy Bear in water. They collect measurements of height, width, and mass before and after the soaking of the candy overnight. Students calculate % change for each factor and graph the data on a bar graph. They then develop a new, testable question and follow through with the new experiment. A copy of the instructions and rubric is provided.
2. The students will calculate the percent change of height, width, and mass, graph the results, and analyze the results.
3. The students will develop an experiment and implement it.
1. Science is a process that continually finds more questions to ask.
2. Osmosis is the transfer of water to equalize two sides of a barrier.
3. Selectively permeable membranes allow some molecules to move through, while not allowing others.
-Active and passive transport
(isotonic, hypertonic,hypotonic--easily would fit too)
Context for Use
Description and Teaching Materials
Students will record their predictions and work in groups to design a data collection table for their expected data.
The procedure of the lab is structured and given to the students. Materials needed: Gummy bears (at least 2 per group), method of measuring height and mass of bear, containers for water. Bears will soak in water overnight, then students will record second set of measurements, calculate % changes, and graph percent changes. Then they will be given definitions of the vocabulary words and asked questions analyzing their results. The students will then develop questions they now have and develop a new experiment based on the new questions. After they have completed their second experiment, they will discuss first in small groups and then as a class their results.
I modified this lab to be more inquiry based from a lab I received at a lesson swap at one of the recent MN Biology Teachers Conference at the Science Museum; I don't have any information about the author of the lesson.
See attached Observing Osmosis handout and rubric. Assignment handout and rubric (Microsoft Word PRIVATE FILE 147kB Sep4 08)
Teaching Notes and Tips
*For high school students, or higher achieving students, it would be easy to include the terms hypertonic, isotonic, and hypotonic and have them determine what types of substances would fit under each term.
*It would be good to remind the students to be careful with their gummy bears on the second day because the bears will probably be fragile.
9-12 IV.A.3 Cell membrane as a selective barrier