Osmosis
The purpose of this lab is to assist you in learning about a
type of diffusion that involves the movement of water. You will examine how
changes in concentration between the inside and outside environments affect
animal (red blood cell known as RBC), plant (elodea) and protist (paramecium)
cells creating three different conditions.
You will go to the following website:
http://www.glencoe.com/sites/common_assets/science/virtual_labs/LS03/LS03.html
You will follow the instructions and work through the simulation
as instructed in the lab.
As you perform the simulation, you will record your results
in the table below (in another color font).
Be sure to consult your textbook, lecture notes, and even the internet
for proper terminology of what you are observing (such as crenation,
plasmolysis, hemolysis, cytolysis, etc.) You must use the proper terminology
when describing the appearance of the cells.
Once you have completed the lab activity and the table, you
will answer the remaining journal questions below. Please answer all questions
in another color font.
Save your file as .doc or .docx and upload it into eCampus
in the proper lab section for grading. Do NOT copy and paste it into the text
box on eCampus.
RBC; Net water movement in/out RBC: appearance of cell Elodea: Net water movement in/out Elodea; appearance of cell Paramecium; net water movement in/out Paramecium; appearance of cell
Hypotonic
Isotonic
Hypertonic
Journal Questions:
1. Did water
move into the cell our out of the cell while it was surrounded by a hypotonic
solution?
2. In which
direction did the water move through the cell membrane when the cell was
surrounded by the hypertonic solution?
3. Compare
and contrast what happens to an animal, a plant, and a protist cell in a
hypotonic solution.
4. Compare
and contrast what happens to an animal, a plant, and a protist cell in an
isotonic solution.
5. Compare
and contrast what happens to an animal, a plant, and a protist cell in a
hypertonic solution.
6. Could
Elodea or Paramecium from a freshwater lake be expected to survive if
transplanted into the ocean? Explain why or why not.
7. If you
were to grill a steak, would it be better to put salt on it before or after you
cook it? Explain why in terms of osmosis.
8. Why does
a salad become soggy and wilted when the dressing has been on it for a while?
Explain why in terms of osmosis.
9. An
effective way to kill weeds is to pour salt water on the ground around the
plants. Explain why the weeds die, using the principles discovered in this
virtual lab.
