Osmosis and Gummy Bears

Ruby Franklin

July 13, 2012

Name______Clalss:______Date:______

Objective:

In this investigation, you will use gummy bears to demonstrate the process of osmosis.

Background:

Water can easily pass through thesemi-permeable cell membranes from both plants and animals. When water moves from an area of high water concentration (low solute concentration) to an area of low water concentration (high solute concentration), this process is called osmosis. This process requires the use of no cellular energy, and flows back and forth until equilibrium of its molecules are reached.

If a cell is placed in an environment in which the concentration of water is less than that inside the cell, the concentration of the solute outside of the cell is greater. This is considered a hypertonic environment. If the concentration of the water is greater than the concentration inside of the cell, the concentration of solute is less. This is considered a hypotonic environment. If the concentration of water in the environment is equal to that of the cell, and the concentration of the solute is equal, both inside and outside of the cell, this is considered an isotonic environment.

This simple process has benefited the sports industry in many ways. In this investigation, you will demonstrate whether this scientific process supports the claims of “Big Business.”

Pre-Lab Questions:

  1. What is a solute? What is a solvent? Can any compound act as a solute or solvent?
  2. Why is water called the universal solvent?
  3. Would osmosis be considered active or passive diffusion? Why?
  4. Read the sample sports drinks label. What ingredients would you find? Why is it not just water?
  5. Which would you think the better product, bottled water or a sports drink?

Materials:

  • 6 Gummy Bears
  • 3 beakers
  • Various solutions of salt
  • Various solutions of sugar
  • Balance
  • Distilled Water

Procedure:

Day 1

  1. Beaker 1: Weigh two gummy bears and put them into a known concentration of a hypotonic solution
  2. Beaker 2: Weigh two gummy bears and put them into a known concentration of a hypertonic solution
  3. Beaker 3: Weigh two gummy bears and put them into distilled water

Day 2

  1. Make your observations.
  2. Devise a data table.
  3. Weigh your results.

Suggestions:

  • Have students calculate the percentage of solute in the gummy bears. Explain.
  • Maybe students have done sweetness and salty thresholds. Have them compare.
  • Graph results of both sweet and salt concentrations.
  • Try solutions of acetic acid.
  • Use various fruits and vegetables of similar mass.
  • Graph the above.
  • Calculate the percentage of water gain or loss in the gummy bears.

Discussion Questions:

  1. Which do you think is better to replenish your thirst, water or Gatorade? Why?
  2. Why do you feel dehydrated after a good workout?
  3. Have companies gone overboard in advertising their brand? Why?

Scott,

This is just a rough idea, because I thought we would have to present the lab. I would normally take more time and make it more attractive to the students. I have done this lab in several ways (the egg, apple, gummy bears, etc.)