Name:_______________________________________ Date:____________ Period:___________________
Gummy Bear Spa Day (Osmosis)
Day 1
Learning Objective:
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At the end of this lab, you will be able to demonstrate and explain the process of osmosis and diffusion using
gummy bears soaked in various solutions.
You will be able to identify the direction of water movement based on concentration gradients and predict the
effect of different solutions on cell size while connecting your findings to the broader concepts of passive
transport and cell membrane selectivity.
Question: Where is the concentration of water molecules highest, tap water or salt water?
Background Information: Molecules are in constant motion and tend to move from areas of higher concentrations to
lesser concentrations. Diffusion is the movement of molecules from an area of high concentration to a low
concentration. The diffusion of water molecules through a selectively permeable membrane is known as OSMOSIS.
Selectively permeable means that some molecules can move through the membrane while others cannot. Movement
through membranes is called transport. Diffusion and osmosis are passive forms of transport; this means they do not
need energy to move areas of high concentration to areas of low concentration. Active transport requires energy to
transport molecules from low concentration to high concentration.
Osmosis is the movement (transport) of water (small dots) through a selectively permeable membrane from an area of
high concentration to an area of low concentration.
Vocabulary:
Add the definitions for each term:
1. active transport ______________________________________________________________________________
2. concentration gradient ________________________________________________________________________
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3. diffusion ____________________________________________________________________________________
4. membrane __________________________________________________________________________________
5. osmosis _____________________________________________________________________________________
6. hypertonic __________________________________________________________________________________
7. hypotonic ___________________________________________________________________________________
8. isotonic _____________________________________________________________________________________
9. passive transport _____________________________________________________________________________
10. selectively permeable _________________________________________________________________________
Answer the following questions before beginning:
1. How will soaking gummy bears in tap water affect the size of the candy?
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2. Prediction: explain your prediction based on your knowledge and the background information
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3. How will soaking gummy bears in saltwater affect the size of the candy?
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4. Explain your prediction based on your knowledge and the background information
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Materials:
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1 cup of tap water
1 cup of salt water
Marker
Ruler
Scale
Wax paper
Spoon
Procedure: DAY 1
1. Label each cup with each group member’s name, class period, and if it contains salt or tap water.
2. Choose one of the gummy bears to put in the tap water and one for salt water.
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Record which color will enter each solution in the data table.
3. Use the ruler to find each bear's height, width, and depth.
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Record your results in the data table on
Round your measurements to the nearest tenth
4. Use the scale to weigh each gummy bear.
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Record your results in the table.
Round your answers to the nearest tenth.
5. Record any other qualitative observations about the gummy bear in the data table.
6. Place one gummy bear into the tap water and the other into salt water to sit until tomorrow’s class.
Procedure: DAY 2
1. GENTLY removed the gummy bear from the tap water from the tap water beaker using a spoon and place it on wax
paper.
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2. Use the ruler to find the height & width of the tap water bear. Record your results in the data table below. Round your
measurements to the nearest tenth.
3. Place the tap water bear on the wax paper and weigh it.
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Record your results in the data table below. Round your answers to the nearest tenth.
5. Record any observations for the tap water bear on the data table below.
6. Place this bear aside on a paper towel.
7. Follow steps 2-6 for the gummy bear in salt water. Record the results in the data table below.
Analysis:
1. Which bear(s) served as the control group(s) in this experiment?
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2. Which bear(s) served as the experimental group(s) in this experiment?
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3. What happened to the bear after soaking it in tap water overnight? Why?
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4. What happened to the bear after soaking it in salt water overnight? Why?
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5. What would happen to the saltwater bear if it were placed back into tap water overnight? Why?
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6. Did the results support your predictions? Why or why not?
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