Labs+and+Activities

Diffusion Lab

=Upper Merion Area High School  Biology=

**__Diffusion Lab__**
=**__Name__________________________________________**=


 * __Background:__**

1. What is Diffusion?

2. What is Osmosis?

3. When does a Hypertonic condition occur? What is the effect on a cell?

4. When does a Hypotonic condition occur? What is the effect on a cell?

5. When does an Isotonic condition occur? What is the effect on a cell?

6. Why is Homeostasis important to maintain?


 * __Objective/ Purpose__**


 * __Hypothesis:__** If solutions containing different concentrations of water are separated by a

membrane, then the water will move from _____________ to _____________ concentration of

water.


 * __Materials__**


 * __Method__**

Using a piece of dialysis tubing tie one end with string Fill the tubing with **__cell solution__** not completely full Tie the other end of tubing forming a sack, pat dry. Mass the tubing and record in data table as initial mass A Place the tubing in a beaker and cover with **__solution A, label beaker A__**
 * __Group 1__**

Using a piece of dialysis tubing tie one end with string Fill the tubing with **__cell solution__** not completely full Tie the other end of tubing forming a sack, pat dry. Mass the tubing and record in data table as initial mass B Place the tubing in a beaker and cover with **__solution B, label beaker B__**
 * __Group 2.__**

Using a piece of dialysis tubing tie one end with string Fill the tubing with **__cell solution__** not completely full Tie the other end of tubing forming a sack, pat dry. Mass the tubing and record in data table as initial mass C Place the tubing in a beaker and cover with **__solution C, label beaker C__**
 * __Group 3.__**

After one day remove the sacks from the beakers, pat dry, and record in the data table the final masses of A, B or C.
 * __All Groups.__**


 * __Data__**

Initial Mass (g) Final Mass (g) Change in Change in Mass (g) Mass (g) (Final-Initial) Class

























Tube A

Tube B

Tube C


 * __Graph__** Using the following graph paper, prepare a bar graph of the effect of the various solutions (x-axis) versus change in mass (y-axis).






































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































 * __Analysis__**

1. Did the masses of all the tubes show the same type and amount of change?

Tube A

Tube B

Tube C

2. Why did the mass of the sacks change?

A

B

C

3. Describe in words or pictures/diagram (show before and after) what would happen to a cell if it were in

Solution A

Solution B

Solution C

4. If you were a cell in which solution would you want to be, why?

5. This lab demonstrated a technique used to determine the concentration of unknown solution in a cell.

Looking at the data, which solution is probably the same as the solution inside the cell (sack). Why?