Chapter 4 Review Sheet
Passive Transport
Diffusion
1. Name three items that can diffuse across the lipid bilayer.
2. How much energy does it take for the cell to undergo passive transport
3. When is diffusion done?
4. What is diffusion (definition)?
Osmosis
5. What is the definition of osmosis?
6. How much energy does a cell expend in performing osmosis?
7. What type of osmotic solution causes water to flow out of a cell?
8. What type of osmotic solution causes water to flow evenly in and out of a cell?
9. What type of osmotic solution causes water to flow into a cell?
10. Why does a hypertonic solution cause plasmolysis?
Facilitated Diffusion
11. What are the selective passageways in the cell membrane used for facilitated
diffusion?
12. What specific passageway do ions use for facilitated diffusion?
13. What is an example of a molecule (not an ion) that uses facilitated diffusion?
14. Why do ions and large polar molecules use facilitated diffusion instead of simple
diffusion like water and oxygen?
Active Transport
15. What are two differences between active transport and passive transport?
16. What is similar between active transport and facilitated diffusion?
17. What is an example of active transport in nerve cells?
Cytosis
18. What is it called when large substances (larger than transport proteins) move into a
cell?
19. What is it called when large substances (larger than transport proteins) move out of a
cell?
20. What happens when secretion occurs?
21. What happens when excretion occurs?
Receptor Proteins
22. List the three things that can occur when a signal molecule attaches to a receptor
protein?
23. What membrane proteins do signal molecules attach to?
24. Receptor proteins attach to what type of molecules?
Answers
1. CO2, O2, H20
2. none
3. equilibrium
4. random movement of molecules from high concentration to low concentration
5. diffusion of water through the cell membrane
6. none
7. hypertonic
8. isotonic
9. hypotonic
10. A high concentration of water inside the cell causes water to leave the cell to the
lower concentration of water outside the cell thus causing the cell to shrink
11. transport proteins
12. ion channels
13. sugar
14. ions and large polar molecules cannot diffuse across the lipid bilayer because of their
charge (ions) or polarity and size. They need a transport protein to ‘help’ them across
15. Energy and going against the concentration gradient (from low to high concentration)
16. transport protein
17. sodium/potassium pump
18. endocytosis
19. exocytosis
20. exocytosis of products
21. exocytosis of wastes
22. 1. change in permeability 2. 2nd messenger 3. catalyze chemical reactions
23. receptor
24. signal