Download What is the Concentration of my Solution

Where (the cell) have you been?
Important Information
• All of your cells were massed at ______________________ yesterday.
Write this for your cells in the row “Mass it started with…”
• All of your cells contain 75% water and 25% concentration of dissolved starch
• The starch cannot go through the membrane, only water molecules
• Hint: one of your cells was in an isotonic solution.
1. Next, you want to mass each cell so you can find out how it changed overnight.
• It’s easier to mass the balloons in the bowl….so mass the bowl by itself first, then
subtract the weight of the bowl from the bowl/balloon mass
2. Compare the mass of what the cell used to be and what it is now. Document how much it
changed (for instance, -5 grams means it shrunk by 5 grams, lost mass)
3. Decide what type of solution the cell must have been in based on how it changed. Document this
in the last row of your data table. (Hypotonic, Isotonic, Hypertonic?)
4. Now, look at the concentrations of the different colored solutions.
•
•
•
●
Based on how your cell changed in mass….and HOW MUCH it changed in mass, decide
which cell was in which one of the solutions. (Each cell was in a different solution)
Match your solution color with the letter on the cell.
Raise your hand when your group is finished and I will check to see if you are correct.
Each person answers their OWN conclusion questions (if you don’t understand, ask me)
Cells
A
B
C
Mass It started
with
Mass After
(subtract bowl)
Difference
+/- and amt.
Type of
Solution cell
was in?
Hypo, Iso, Hyper?
Solution
GREEN
YELLOW
PURPLE
BLUE
RED
Solution
Concentration of
Starch
Which Cell was in
this solution?
D
E
Name:
Osmosis Activity Conclusion
1. What happens with the direction of osmosis (water flow) if a cell is put in an isotonic solution?
2. How did you determine which cell was in the isotonic solution?
3. What happens with the direction of osmosis (water flow) if a cell is put in a hypotonic solution?
4. How did you determine which cells were in the hypotonic solutions?
5. What happens with the direction of osmosis (water flow) if a cell is put in a hypertonic solution?
6. How did you determine which cells were in the hypertonic solutions?
7. Why would it have been impossible to do this lab if I hadn’t given you the mass of the “cells” before
they were put in the solution?
8. What is a major difference between a plant cell being put in a hypotonic solution and an animal cell
being put in a hypotonic solution?