Name:____________________________
Lab Partners:____________________________________________________
Mrs. Gomez
Biology
Due Date:_________________________
Osmosis Potato Lab
Introduction:
Purpose: The purpose of this lab is to determine what percent of sugar each type of
osmotic solution will occur. Potato pieces will be placed in fresh water, and three
types of sugar solutions, the direction of water movement will be determined based
on the sugar concentration of the potato.
Background: Answer the following questions within the body of your lab report.
1. What is diffusion? Give an example.
2. What is osmosis?
3. Describe the three types of osmotic solutions.
4. Give at least one example of a way you can create a hypertonic solution and one
way you can create a hypotonic solution within your body.
5. Explain why water moves (equilibrium)
**Be sure to make proper citations from the textbook or other source (Biggs et al, Pg #)
Hypothesis: Complete the following statements:
The freshwater will be a _______________solution because.......
The 2% sugar solution will be a ________________solution because..
The 4% sugar solution will be a ________________solution because..
The 6% sugar solution will be a ________________solution because..
Design Setup:
Attach a hand drawn diagram to the lab, you may also use some clip art
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All materials used
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Label materials
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Label all solution types
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Provide a purpose or justification for each material
Materials:
1. Beakers or plastic cups, 4
2. fresh water, 40 mL
3. 2% sugar water, 40 mL
4. 4% sugar water, 40 mL
5. 6% sugar water, 40 mL
6. Potato pieces, 4 pieces
7. triple beam balance
8. paper towels
9. forceps
10.marker
Procedure:
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Collect all materials
Pat pieces of potato dry with paper towel
Place each piece of potato is a different beaker and label the beakers
Remove piece of potato and weigh using the triple beam balance
Record each weight in grams in your table
In beaker A add 40mL of freshwater from flask
In beaker B add 40mL of 2% sugar solution
In beaker C add 40mL of 4% sugar solution
In beaker D add 40mL of 6% sugar solution
Label the beakers with pod names and place in safe place, allow to sit for 48
hours
After 48 hours, remove potato from beaker and pat dry with paper towel
Weigh each potato with triple beam balance and record in table
Discard potato pieces, paper towel and solutions
Determine the change in mass (final mass - initial mass)
Determine the % change in mass (change in mass/initial mass)
Determine if the solution is isotonic, hypertonic or hypotonic based on the
movement of water
Graph the % change as a line graph (x-axis - solution, y-axis - % change)
Data:
Potato A
Potato B
Potato C
Initial Mass (g)
Final Mass (g)
Change in Mass (g)
% Change in Mass
Movement of water
Type of solution
make sure you explain what data you are showing in the table
Potato D
Graph your data and make sure you explain the graphs
Calculate the isotonic solution
Analysis:
Explain what happen in the lab, which potato gained/lost mass and how you justified the
type of solution
Conclusion:
1.
Restate purpose statement
2.
Restate your hypothesis
3.
Accept, reject or partially accept your hypothesis and explain (This is where
you need to bring in supporting data)
4.
Explain what type of solution was in each beaker
5.
Use the solution terms and terms that you have used within the introduction
6.
Estimate the % sugar in the potato based on your data (predict the isotonic
solution)
Possible Errors and Critical Thinking:
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What are some possible errors (human, experiment?)
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Why is it important to understand osmosis
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What is a question that you came up with during the experiment that
could have affected your data
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What did you learn from this lab
Works Cited: create a bibliography using MLA format
Textbook:
Biggs, Alton, and Whitney C, Hagins. Biology: The Dynamics of Life. New
York: McGraw Hill Companies, Inc. 2004.
Make sure to include any other sources that you used.
Helpful Hints:
 Double Space
 Keep data tables and graphs on one page
 underline heading and space after sections
 set margins at 1 inch
 NO PERSONAL PRONOUNS
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Have someone proof read your report
Make sure everything is labeled properly (graphs, tables, design setup, etc.)
Do not forget to turn in sections of your lab report (Design setup, graphs, etc.)
Read and follow your lab report rubric, you need to include more detail than is
included here in order to get a 5
 Do not forget units anywhere
 Look over your final product and check the formatting