Download Surface Area and Cell Size Lab

NAME__________________________________
Period______
Diffusion and Osmosis Lab - Part 1 - Surface Area and Cell Size
Cell size and shape are important factors in determining the rate of diffusion. Think about cells with
specialized functions, such as epithelial cells that line the small intestine or plant root hairs.
- What is the shape of these cells?
- What size are the cells?
- How do intestinal epithelial and root hair cells function in nutrient procurement?
Nerve cell
Plant root hair
Procedure (Teacher may demonstrate steps 1-3)
1. Place a few drops of phenolphthalein in two test tubes.
2. Add a few drops of 0.1M HCl to one test tube and swirl to mix.
3. Add a few drops of 0.1M NaOH to the other test tube and swirl to mix.
Intestinal epithelial cell
a. Which solution is an acid? __________________________________________________
b. Which solution is a base? ___________________________________________________
c. What color is the dye in the base? ____________________________________________
d. What color is the dye in the acid? _____________________________________________
4. Use the ruler to cut 3 different sized blocks of agar from the cube provided. These blocks will be the
models for your cells.
e. Complete the table below:
Surface Area
Volume
Cell 1
___________
___________
Cell 2
___________
___________
Cell 3
___________
___________
f. If you put each of the blocks into a solution, into which block would that solution diffuse throughout
the entire block fastest? __________________________________________________________
Slowest? ______________________________________________________________________
Explain _______________________________________________________________________
5. Use the back of this piece of paper to design and record (using a data table) an experiment using your
artificial cells to test your hypotheses regarding surface area and volume.
Which solution will you place the cubes in? How will you measure the diffusion rate into the cell ?