IB Biology Name Cell Membrane Bubble Lab Period

ib biology name _________________________________ cell membrane bubble lab period ______ date ____________________ procedure: mix 50 ml jo

IB Biology Name _________________________________
Cell Membrane Bubble Lab Period ______ Date ____________________
Procedure: Mix 50 mL Joy liquid soap, 500mL water and 2 mL Karo Syrup
in a large, shallow dish. Use two straws and 100% cotton thread to
complete the activity. Do not dump out the solution or throw away the
props at the end of this lab unless instructed to do so by the
teacher.
Properties of Cell Membranes: flexible, fluid, self-sealing, pores,
integral proteins, peripheral proteins
1. Make a film of bubble solution using your straw device and move the
device from side to side to bend the film. What does this illustrate
about a cell membrane?
2. Wet a piece of thread (tied into a circle) in the solution and
gently place it on the cell membrane. Make sure your fingers are wet
when doing this. Now pop the bubble inside the thread. Move the circle
around to show movement of the pores in the membrane. Write down your
observations.
3. Gently remove the circle of thread from the bubble. What happens?
______________________________
What does this illustrate about the cell membrane?
_________________________________________
Why is this a necessary property of the cell membrane?
________________________________________
4.
Float the circle of thread on the cell membrane again. Try
inserting a dry pencil or dry finger through the center of the
thread. What happened?
______________________________________________________
What does this symbolize about the cell membrane?
5. Remove the circle and try inserting your wet finger or wet pencil
halfway through the membrane. Move the pencil around. Describe what
happens. ______________________________________
______________________________________________________________________________
What does this (the pencil stuck in the membrane) symbolize about the
cell membrane?
6.
Wet another straw in the bubble solution. Gently blow bubbles onto
the membrane. What could the bubbles represent?
7. Using the soapy solution, form a prokaryotic cell on the surface of
your lab table. Be sure to include chromatin (DNA) in your model. Show
your teacher your model. Teacher's initials ______
8.
Evolve your prokaryotic cell into a eukaryotic cell. Be sure to
include membrane-bound organelles and an organized nucleus with
chromatin. Show your teacher your model. Teacher's initials ______
9. Describe what was different in your prokaryotic and eukaryotic
cells.