Apple OSMOSIS LABName:
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)Obtain 3 plastic beakers and 3 pieces of aluminum foil to use as covers.
2)Get 6 apple cores of approximately the same size and cut the skin off (2 cores for
each beaker)
3)Take the mass of the cores that will be used in each beaker:
4)Tape a label onto each beaker with group names and sugar solution concentration
5)Lay the cores at the bottom of each beaker
6)Put about 20mL of the correct solution in each beaker (enough to fully cover the
Cores)
7)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**Percent Change in Mass = Final Mass – Initial Mass x 100
Initial Mass
Graph Data
- Using the class data, calculate the average percent change in mass for potatoes in each sugar solution.
- 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.