Lab 4 Diffusion and Osmosis BIO201L
Student Name: Gloria Arajulu
Access Code (located on the lid of your lab kit): AC-OF2X1AP
Pre-Lab Questions:
”1.
1. Compare and contrast diffusion and osmosis.
osmosis.”
Diffusion and osmosis are both passive transport processes. Diffusion involves the movement of
particles from an area of high concentration to low concentration, while osmosis specifically
refers to the movement of water across a semipermeable membrane fro from
m an area of lower
solute concentration to higher solute concentration
concentration.
”2.
2. What is the water potential of an open beaker containing pure water? ”
The water potential of an open beaker containing pure water is 0 (zero). In an open system, like
an open beaker, there is no pressure acting on the water, and pure water has the highest water
potential, which is considered the reference point
point.
”3.
3. Why don’t red blood cells swell or shrink in blood? ”
Red blood cells
ells don't swell or shrink in blood because the blood plasma has the same
concentration of solutes as the cells, creating an isotonic environment that prevents water
movement.
Experiment 1: Diffusion through a Liquid
Table 1: Rate of Diffusion in Corn Syrup
Time (sec) Blue Dye Red Dye
10 1.5 cm 2 cm
20 1.9 cm 3 cm
30 2.2 cm 3.6 cm
40 2.4 cm 4.1 cm
50 2.4 cm 4.2 cm
60 2.5 cm 4.3 cm
70 2.7 cm 4.4 cm
80 2.8 cm 4.4 cm
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, Lab 4 Diffusion and Osmosis BIO201L
Time (sec) Blue Dye Red Dye
90 2.8 cm 4.6 cm
100 3 cm 4.7 cm
110 3.9 cm 4.9 cm
120 3.3 cm 5.1 cm
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 g/mole 18 mm 540 mm/hr
Red Dye 496 g/mole 31 mm 930 mm/hr
*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? ”
This study source was downloaded by 100000902171055 from CourseHero.com on 12-09-2025 23:40:39 GMT -06:00
https://www.coursehero.com/file/209063043/lab-5pdf/
Student Name: Gloria Arajulu
Access Code (located on the lid of your lab kit): AC-OF2X1AP
Pre-Lab Questions:
”1.
1. Compare and contrast diffusion and osmosis.
osmosis.”
Diffusion and osmosis are both passive transport processes. Diffusion involves the movement of
particles from an area of high concentration to low concentration, while osmosis specifically
refers to the movement of water across a semipermeable membrane fro from
m an area of lower
solute concentration to higher solute concentration
concentration.
”2.
2. What is the water potential of an open beaker containing pure water? ”
The water potential of an open beaker containing pure water is 0 (zero). In an open system, like
an open beaker, there is no pressure acting on the water, and pure water has the highest water
potential, which is considered the reference point
point.
”3.
3. Why don’t red blood cells swell or shrink in blood? ”
Red blood cells
ells don't swell or shrink in blood because the blood plasma has the same
concentration of solutes as the cells, creating an isotonic environment that prevents water
movement.
Experiment 1: Diffusion through a Liquid
Table 1: Rate of Diffusion in Corn Syrup
Time (sec) Blue Dye Red Dye
10 1.5 cm 2 cm
20 1.9 cm 3 cm
30 2.2 cm 3.6 cm
40 2.4 cm 4.1 cm
50 2.4 cm 4.2 cm
60 2.5 cm 4.3 cm
70 2.7 cm 4.4 cm
80 2.8 cm 4.4 cm
This study source was downloaded by 100000902171055 from CourseHero.com on 12-09-2025 23:40:39 GMT -06:00
https://www.coursehero.com/file/209063043/lab-5pdf/
, Lab 4 Diffusion and Osmosis BIO201L
Time (sec) Blue Dye Red Dye
90 2.8 cm 4.6 cm
100 3 cm 4.7 cm
110 3.9 cm 4.9 cm
120 3.3 cm 5.1 cm
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 g/mole 18 mm 540 mm/hr
Red Dye 496 g/mole 31 mm 930 mm/hr
*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? ”
This study source was downloaded by 100000902171055 from CourseHero.com on 12-09-2025 23:40:39 GMT -06:00
https://www.coursehero.com/file/209063043/lab-5pdf/
