Vista Murrieta High School
AP Biology
G. Nicholas
Diffusion and Osmosis Lab Questions
Answer the following questions and/or perform the following procedures paying special
attention to using your data to support your answers.
Procedure 1:
1) Why are cells small?
Give a specific examples of the following:
a) tissues/organs in the human body where surface area is maximized for
efficiency.
b) other than mammals, give a specific example in nature where surface
area is maximized for efficiency
- Make sure to answer what, how, and why!
Procedure 2:
2) You are in the hospital and need intravenous fluids. You read the label on the
IV bag, which lists all of the solutes in the water.
a) Why is it important for an IV solution to have salts in it?
b) What would happen if you were given pure water in an IV?
c) How would you determine the best concentration of solutes to give a
patient in need of fluids before you introduced the fluids into the patients
body?
3) How can you use weights of the filled cell models to determine the rate and
direction of diffusion? What would be an appropriate control for the procedure
you just described?
4) Suppose you could test other things besides weights of the dialysis tubes.
How could you determine the rates and directions of diffusion of water, sucrose,
NaCl, glucose, and proteins?
5) Will protein diffuse? (remember, they are big, huge molecules) W ill it affect
the rate of diffusion of other molecules?
6) Which pair(s) of dialysate bags that you tested did not have a change in
weight? How can you explain this?
7) If you compared 1 M solutions, was a 1 M NaCl solution more or less
hypertonic than a 1 M sucrose solution? What is your evidence? What about
1 M NaCl and 1 M glucose and 1 M sucrose? If you didn’t use 1molar solutions,
make an educated guess and back you answer with your data.
8) Would a protein solution have a high molarity? What is evidence for your
conclusion?
9) How could you test for the diffusion of glucose?
10) Based on what you learned from your experiment, how could you determine
the solute concentration inside a living cell?
