Chapter 7 Review: Cells
Name: ___ANSWER KEY_________________
1. Explain the structure and functions of the cell membrane. Draw a phospholipid.
- The cell membrane is a phospholipid bilayer. Its function is to control what goes in
and out of a cell
2. The “tails” of the phospholipids are lipids and fear water, therefore they are
________hydrophobic______________.
3. The “heads” of the phospholipids are water loving, therefore they are
__________hydrophilic______________.
4. What is passive transport? – Hint does it require energy?
- The movement of molecules from high to low concentration, which does not require
energy
5. There are 3 forms of passive transport that we discussed, diffusion is one example,
what are the other two?
Osmosis
Facilitated Diffusion
6. Does diffusion, osmosis, and facilitated diffusion require energy?
They do not require the input of energy
7. Define osmosis and diffusion. In which direction do the molecules flow?
Osmosis is the net movement of water from an area of high concentration of water to
low concentration of water. Molecules flow WITH their concentration gradient
8. Explain how active transport differs from passive transport.
- Active transport is the net movement of molecules from low to high concentration and
energy is required
9. Complete the following Venn Diagram
Endocytosis
Exocytosis
BOTH
-Moving molecules
Into a cell
molecules
- form of active
transport
-requires energy
10. Define the following:
Solute: what is DISSOLVED in a solution (salt)
Solvent: what is doing the DISSOLVING (water)
Solution: a mixture of solute and solvent
- Moving
out of
a cell
11. Define the following:
Hypertonic solution: a solution with HIGHER solute than solvent
Hypotonic solution: a solution with LOWER solute than solvent
Isotonic solution: a solution where the solute and solvent are equal
12. What happens to a cell when it is put into the following solutions? (drawing a picture may be
helpful)
a. hypertonic solution
- the cell will LOSE water and shrink
b. isotonic solution
- water will move into and out of the cell at an equal rate, no change in size
c. hypotonic solution
- the cell will GAIN water and increase in size
13. Why can it be deadly to drink excessive amounts of salt water?
- it can dehydrate your cells
14. Why can it be deadly to drink EXCESSIVE amounts of water?
- it can cause your cells to gain water and burst
15. When should you drink Gatorade and why?
- when you are sweating and losing not only water but salts, Gatorade is typically hypertonic to
the cells.