Lab 4 Diffusion and Osmosis BIO201L
Student Name: Holly Kocian .
Access Code (located on the lid of your lab kit): AC-2BLIE41
Pre-Lab Questions:
”1. Compare and contrast diffusion and osmosis.”
With Diffusion both the solvent and solute particles can cross the membrane, with osmosis only
the solvent crosses the membrane. Both are passive transports.
”2. What is the water potential of an open beaker containing pure water? ”
The water potential is 0
”3. Why don’t red blood cells swell or shrink in blood? ”
Blood is an isotonic solution
Experiment 1: Diffusion through a Liquid
Table 1: Rate of Diffusion in Corn Syrup
Time (sec) Blue Dye Red Dye
10 10mm 12mm
20 13mm 14mm
30 14mm 15mm
40 14mm 17mm
50 15mm 19mm
60 15mm 20mm
70 16mm 22mm
80 16mm 24mm
90 17mm 24mm
100 17mm 25mm
17mm
26mm
110
.
, Lab 4 Diffusion and Osmosis BIO201L
120
18mm 26mm
Table 2: Speed of Diffusion of Different Molecular Weight Dyes
Total Distance Speed of Diffusion
Structure Molecular Weight
Traveled (mm) (mm/hr)*
Blue Dye 793 18mm 540
Red Dye 496 26mm 780
*To get the hourly diffusion rate, multiply the total distance diffused by 30.
Post-Lab Questions
” 1. Examine the plot below. How well does it match the data you took in Table 1? ”
The plot is very similar to my data
”2. Which dye diffused the fastest? ”
Red
”3. How does the rate of diffusion correspond with the molecular weight of the dye? ”
Since the weight of the Red Dye is less than the weight of the Blue dye it therefore diffuse
Student Name: Holly Kocian .
Access Code (located on the lid of your lab kit): AC-2BLIE41
Pre-Lab Questions:
”1. Compare and contrast diffusion and osmosis.”
With Diffusion both the solvent and solute particles can cross the membrane, with osmosis only
the solvent crosses the membrane. Both are passive transports.
”2. What is the water potential of an open beaker containing pure water? ”
The water potential is 0
”3. Why don’t red blood cells swell or shrink in blood? ”
Blood is an isotonic solution
Experiment 1: Diffusion through a Liquid
Table 1: Rate of Diffusion in Corn Syrup
Time (sec) Blue Dye Red Dye
10 10mm 12mm
20 13mm 14mm
30 14mm 15mm
40 14mm 17mm
50 15mm 19mm
60 15mm 20mm
70 16mm 22mm
80 16mm 24mm
90 17mm 24mm
100 17mm 25mm
17mm
26mm
110
.
, Lab 4 Diffusion and Osmosis BIO201L
120
18mm 26mm
Table 2: Speed of Diffusion of Different Molecular Weight Dyes
Total Distance Speed of Diffusion
Structure Molecular Weight
Traveled (mm) (mm/hr)*
Blue Dye 793 18mm 540
Red Dye 496 26mm 780
*To get the hourly diffusion rate, multiply the total distance diffused by 30.
Post-Lab Questions
” 1. Examine the plot below. How well does it match the data you took in Table 1? ”
The plot is very similar to my data
”2. Which dye diffused the fastest? ”
Red
”3. How does the rate of diffusion correspond with the molecular weight of the dye? ”
Since the weight of the Red Dye is less than the weight of the Blue dye it therefore diffuse
