Name_______________________________ Period___________ Date________________
Unit 3
Lab
Osmosis in Gummy Bears
Introduction: Molecules in solution are in constant motion, and tend to move from areas of
higher concentrations to areas of lower concentrations. This process is called diffusion. The
diffusion of water through a selectively permeable membrane is known as osmosis. Diffusion
and osmosis are passive forms of transport that do not require the input of energy.
Background Information:
1. Key terms: Hypertonic = _______________ concentration of solute
Hypotonic = _______________ concentration of solute
Isotonic = _______________ concentrations of solute
**Remember: Water moves from hypotonic to hypertonic solutions!**
2. We will use gummy bears to represent living cells because they are small and contain
dissolved substances.
Gummy bear ingredients: _______________________
_______________________
_______________________
Experimental Question: How will soaking gummy bears in water affect their size?
Hypothesis (include an explanation of your hypothesis): _______________________________
_____________________________________________________________________________
_____________________________________________________________________________
_____________________________________________________________________________
_____________________________________________________________________________
Materials:
gummy bears
water
beaker
ruler
Procedure: Part I
1. Using a ruler, measure the height and width of 5 gummy bears to the nearest millimeter.
Record your results in the table below. Then find the average height and width of all 5.
Table 1: Size of gummy bears before soaking
1
2
3
4
5
Average
Height
Width
2. Place your gummy bears in a beaker of water and leave overnight.
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Procedure: Part II
3. The next day, GENTLY take the gummy bears out of the water and pat them dry. Repeat step
1 and record your results in table below.
Table 2: Size of gummy bears after soaking
1
2
3
4
Height
Width
4. When finished, throw away all trash and wash all equipment.
5
Average
Data Analysis:
1. Create a bar graph that shows the average height and width of your gummy bears before
AND after soaking. Remember to label your axes.
2. Calculate the percent change in size (using the average width and height) of the gummy
bears. Use the formulas below.
Change in width = (Difference in width) ÷ (Original width) x 100% = _______________
Change in height = (Difference in height) ÷ (Original height) x 100% = _______________
Conclusion:
1. What would happen to the gummy bears if you soaked them in salt water over night? Explain.
2. Write a one paragraph (4-6 sentences) conclusion that summarizes your results. Make sure to
include:
What happened to the gummy bears? (Cite specific data!)
Why did you get these results? (Use the terms osmosis, diffusion, hyper/hypotonic)
Did you support or reject your hypothesis? Why or why not?