Name: __________________________________
Date: __________________________
Science Department
Essential Biology
Unit Three – Cell Transport: Homework
Diffusion and Osmosis
1. What is a solute?
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2. What is a solvent?
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3. What is diffusion?
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4. In which direction do molecules move in diffusion (from where to where)?
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5. When and why does diffusion stop?
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6. What is a concentration gradient?
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7. What does it mean when a solution or system has reached equilibrium?
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8. What is osmosis?
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9. What does semipermeable mean?
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10. Describe the movement of water molecules in osmosis.
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Facilitated Diffusion, Passive and Active Transport
11. What is facilitated diffusion?
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12. Describe the movement of particles in facilitated diffusion.
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13. How does facilitated diffusion affect the rate of the movement of some particles?
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14. How are the processes of diffusion, osmosis, and facilitated diffusion alike?
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15. What term can we use to describe the processes named in question #4?
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16. What is active transport?
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17. In which direction do particles move in active transport?
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18. How are active and passive transport different from each other?
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19. How are active transport and facilitated diffusion alike?
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20. Describe the sodium-potassium ion pump and explain why it is so important to your body.
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Bulk Transport
21. What is bulk transport?
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22. What are the two types of bulk transport?
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23. Describe the movement of particles in exocytosis.
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24. Describe the steps in the process of exocytosis.
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25. Describe the movement of particles in endocytosis.
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26. Describe the steps in the process of endocytosis.
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27. What is a vesicle and what is it used for?
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28. Name the two types of endocytosis and describe each.
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2.__________________________________________________________________________________
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29. Fill in the chart below by filling in yes or no.
ACTIVE TRANSPORT
FACILITATED DIFFUSION
DIFFUSION
Requires energy
Moves molecules against their
concentration gradient
Requires a membrane protein
Sodium-potassium ion pump is
an example
30. Compare and contrast facilitated diffusion and active transport.
Similarity (1) : ___________________________________________________________________
Differences (two):
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B: ______________________________________________________________________________
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31. Fill in the chart below.
Type of Solution 
Describe in each box
what happens to a cell
when placed in that
type of solution.
ISOTONIC
HYPERTONIC
HYPOTONIC