Hypertonic to Hypotonic Flow - Osmosis! Let's Go!

Sixth graders have completed a lab on osmosis using gummy bears as a model of the cell.  The masses of three gummy bears were determined.  One was placed in an empty cup as a control.  One was placed in 250ml of water, and the final one was placed in 250ml of water in which a sugar cube had been added. 

Osmosis is the diffusion of water from an area of greater concentration to lesser concentration.   The bears that had been placed in sucrose water and tap water increased in mass after 72 hours by an average of 9 grams and 11 grams respectively.  The masses of the control bears stayed the same.

Students concluded that the bears were hypotonic to the water and therefore the water from the cup diffused through the outer membrane of the bears through osmosis into the gummy bear. 

Qualitative data was recorded as well.  Bears became soft, slimy and more fragile.