Cell Membrane Lab Report

BioLab3 Cell Membranes Lab Report

Student Name:

I. Diffusion

Define the following terms.
Solvent

Solute

Solution.

Diffusion

Concentration gradient

Dynamic equilibrium

EXERCISE 1 – Factors influencing rate of diffusion

Predict how molecule size and temperature will affect the outcome of this experiment.

Record the data from the information in the lab.
Potassium Permanganate R.T.
Methylene Blue R.T.
Time (min)
Total Diameter
(mm)
Distance of Diffusion * (mm)
Rate (mm/min) *
Total Diameter
(mm)
Distance of Diffusion * (mm)
Rate (mm/min) *
0

15

30

45

Potassium Permanganate 5 Celsius
Methylene Blue 5 Celsius
Time (min)
Total Diameter (mm)
Distance of Diffusion * (mm)
Rate (mm/min) *
Total Diameter
(mm)
Distance of Diffusion * (mm)
Rate (mm/min) *
0

15

30

45

* Distance diffused = diameter of each reading minus initial diameter Rate = distance in mm/elapsed time (min)

Double click the chart below. A spreadsheet will open. Enter the data from the table above into the spreadsheet in the areas provided. When you are finished, click into another area of the lab report. The spreadsheet will close automatically. Do not close the spreadsheet with the X in the upper right corner.

What effect did temperature have on the rate of diffusion?

How did molecule size affect the rate of diffusion?

What happens to the rate of diffusion over time? Why?

What can you conclude from this experiment?

II. Osmosis

Define the following terms.
Osmosis

EXERCISE 2 – Osmosis demonstration

After 15 minutes, record the volume change in each tube.
Osmometer
Dialysis Tube Contents
Beaker Contents
Volume Fluid Moved
Direction of Movement
1

2

Describe the net movement of water in osmometer 1.

Describe the net