Bi 12
B9 – Cell Membrane and Transport
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1. Label the diagram below.
2. Where are the HYDROPHOBIC regions of the membrane? The HYDROPHILIC regions? Label
these regions on the diagram.
3. On the diagram, label the two types of molecules that make up the structure that is labeled “E”.
A.
B.
C.
D.
E.
F. (same things)
4. Permeability of Our Membranes
a. Our membranes are said to be selectively
permeable. What does this mean?
b. What types of molecules find it easy to
move through our membranes? Why?
c. What types of molecules find it difficult to
move through our membranes? Why?
5. Biological Molecules in the Membrane:
Molecule
Skeleton (simple) diagram (sketch)
Glycoprotein
Function in Membrane
Bi 12
B9 – Cell Membrane and Transport
Glycolipid
(Carbohydrate)
(not found alone in the membrane, but
you need to know this for later anyway –
might just as well add it here!)
(Function with membrane AND in body)
(for comparison to phospholipids)
(Function in body)
Cholesterol
Phospholipids
Fatty Acids
Proteins
Lipids
(triglycerides)
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Bi 12
B9 – Cell Membrane and Transport
Channel
protein
Carrier protein
Receptor
Protein
6. Describe the differences
Processes
Endocytosis
vs Exocyosis.
pinocytosis
vs.
phagocytosis
diffusion vs
osmosis
Differences
3
Bi 12
B9 – Cell Membrane and Transport
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9. For each of the next three examples, identify whether the solution is isotonic, hypertonic or
hypotonic compared to the “cell”, DESCRIBE what will happen to the cell and explain WHY.
10. Complete the following table:
Do the molecules
Is the use of
Transporter
follow their
energy
process
concentration
required for
gradients with this this process?
process?
Diffusion
Osmosis
Facilitated
Transport
Active
Transport
Endocytosis
exocytosis
Is a channel
or carrier
protein used
in this
process?
What types and/or sizes of
molecules are transported using
this process?
Bi 12
B9 – Cell Membrane and Transport
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11. Describe how the RATE of diffusion across a cell membrane is affected by each of the following factors:
Factor
How it affects the rate of diffusion.
a. temperature
b.
size of molecule
c. charge of molecule
d. concentration
gradient
e. pressure gradient.
12. Identify the type of membrane transport in the diagrams below, and classify them as either passive or
active transport.
b.
a.
c.
e.
d.
f.
Transport
Type
a.
b.
c.
d.
e.
f.
Active
Or
Passive?