POTATO=OSMOSIS
=EXPERIMENT=
All living things are made of cells which are differentiated to perform different functions. Substances move
into or out of the cell and enzymes are catalysts contributing to cell metabolism. Osmosis, the process in
which solvent molecules move from an area of lower solute concentration to an area of higher solute
concentration, can easily be demonstrated with potato experiments. Potatoes are full of both water and
starch, and will gain water when immersed in watery solutions. Conversely, they will lose water when in
concentrated solutions, such as those containing a great deal of starch.
Materials:
• 1 potato
• 5 cups
• Water
• Salt
• Sugar
• Paper
• Pencil
• Ruler
• A spoon
• Towel paper of a plate
Procedure:
1. Peel and cut the potato into 5 thin slices such as French fries, make sure they
have the same size or almost the same size.
2. Measure the 5 slices with a ruler and record your data
3. Place the 5 cups with the same amount of water (about 8 cm)
4. The first cup will be your control group, place one slice into the tap water and
label it as control.
5. Place 2 tablespoons of salt on the second cup, stir it, and sink a slice. Label
this as 2 tsp. of salt.
6. Place 5 tablespoons of salt on the third cup, stir it, and sink a slice. Label this
as 5 tsp. of salt.
7. Place 2 tablespoons of sugar on the second cup, stir it, and sink a slice. Label
this as 2 tsp. of sugar
8. Place 5 tablespoons of sugar on the third cup, stir it, and sink a slice. Label
this as 5 tsp. of sugar
9. Leave your experiment over night and the next day place the slices on a
tower paper or plate and measure the size of the slices. Record your data.
Questions
a)
b)
c)
d)
e)
What are the independent and dependent variables in this experiment?
How does the size of potato slices change with salt and sugar concentration?
Which substances moved across the cellular membrane in this activity?
Why is salty water a good way to preserve vegetables?
Based on the experiment, why isn’t good to drink seawater when lost at sea?
Potato Osmosis Report
Your report must include
 Front page
 Information about your experiment.
 Data tables and graphs
 Conclusions
 Attachments (pictures of your experiment)
.