Apple OSMOSIS LAB
Name:
Background Information: What do you know?
1. Water moves through cell membranes from areas of ________concentration to areas
of ________concentration.
2. If a solute such as sugar is dissolved in water, it forms a _________.
3. If different amounts of sugar are dissolved in water, you create different sugar
_______ with different ________.
4. The more sugar in the solution the _______ the water concentration.
5. Apple cells have a certain amount of ________ and ________ in their cells.
6. Placing apples in different sugar solutions will cause ______ of water to occur. This
movement of water is called ________.
Focusing Question:
Hypothesis: What can you predict will happen in different sugar solutions?
1. If apples are placed in a hypotonic sugar solution (lower concentration of sugar
outside), water should________the cells and the potatoes will ________mass.
2. If apples are placed in a hypertonic sugar solution (higher concentration of sugar
outside), water should ________the cells and the potatoes will ________mass.
3. If apples are placed in an isotonic sugar solution, no net gain in or out occurs (no
change in weight).
Materials:
- Plastic beakers with aluminum foil lids
- masking tape
- apple borers
- 3 different solutions 0% Sugar, 80% Sugar, 20% Sugar
- Apple cores into with no skin
- Electronic balances
Procedure:
DAY 1
1)
2)
3)
4)
5)
6)
7)
Obtain 3 plastic beakers and 3 pieces of aluminum foil to use as covers.
Get 6 apple cores of approximately the same size and cut the skin off (2 cores for
each beaker)
Take the mass of the cores that will be used in each beaker:
Tape a label onto each beaker with group names and sugar solution concentration
Lay the cores at the bottom of each beaker
Put about 20mL of the correct solution in each beaker (enough to fully cover the
Cores)
Cover each beaker with aluminum foil and place back on the cart
DAY 2
Drain sugar solution from each jar
Pat apple cores dry and take their final mass
Record the initial mass and the final mass on the data sheet for each concentration
Place apples in the garbage and wash and dry the plastic beakers
Calculate the percent change in mass for each jar
Data
Sugar concentration
(M)
Initial Mass (g)
Final Mass (g)
*Percent Change in Mass = Final Mass – Initial Mass
Initial Mass
x
Percent change in
mass*
100
Graph Data
1. Using the class data, calculate the average percent change in mass for potatoes in
each sugar solution.
2. Identify the following: Independent variable =
Dependent variable =
Control Group =
3. Plot the points: x axis =
y axis =
4. Draw a line of best fit for the plotted points
5. Use a descriptive title that explains the contents of the graph:
Analysis
Use complete sentences
1. What possible sources of error exist for data collection and analysis in this lab? Be
specific.
2. In which sugar solution(s) did the cores lose mass?
3. In which sugar solution(s) did the cores gain mass?
4. Which sugar solution(s) were hypotonic to the cores? Explain your anwer with data
5. Which sugar solution(s) were hypertonic to the cores? Explain your answer
6. Use your graph to determine the concentration of sugar in your apples. Explain your
reasoning. Be specific.