Cell Transport 1.4 Study Guide
1. Define selectively permeable in the context of the plasma membrane.
2. Define diffusion.
3. Define osmosis.
4. List three ways to maximize the rate of diffusion of a substance across a membrane.
5. Outline the conditions required for the following methods of membrane transport:
Simple
diffusion
Osmosis
Facilitated
diffusion
Active
transport
Concentration
gradient
Selectively
permeable
membrane.
Membrane
proteins
yes
Yes
no
6. ATP
(source
of
energy)
7. no
Yes
8.
yes
9.
yes
10.
11. State the membrane transport methods used by the following molecules:

Water:

Non-polar molecules (with the concentration gradient):

Polar molecules (with the concentration gradient):

Any molecule against the concentration gradient:

Macromolecules (large molecules) (with the concentration gradient):
12. Explain what is happening in this diagram:
13. Draw and annotate a diagram to show how a protein pump is used in active transport. Show all 6
steps. (Sodium-Potassium pump is an example)
14. Complete and annotate the diagram below to show the process of vesicle transport of a protein
molecule through a eukaryote cell. Begin with protein synthesis in the Rough ER and finish with
exocytosis though the plasma membrane. Label all organelles shown.
15. Distinguish between exocytosis and endocytosis.
16. Describe how the plasma membrane breaks and reforms during exocytosis and endocytosis.
How does the fluidity of the membrane allow this?
1. A study was carried out to determine the relationship between the diameter of a molecule
and its movement through a membrane. The graph below shows the results of the study.
High
Relative ability to move
through a membrane
Low
0
0.4
0.8
1.2
Molecular diameter / nm
[Source: Knox, et al., Biology, Mcgraw Hill, Sydney, 1994, page 65]
(a)
From the information in the graph alone, describe the relationship between the
diameter of a molecule and its movement through a membrane.
1.6