Cell Transport Study Guide
1. Which forms of transport do NOT
require energy?
• Diffusion
• Osmosis
• Facilitated Diffusion
*All of these are passive!
2. Which forms do require energy?
• Endocytosis
• Exocytosis
• Sodium-Potassium Pump
*All of these are active!
3. At the end of the diffusion process,
the concentration of substances on
each side is _____________.
• Equal
4. Draw an illustration of diffusion.
• On right side of board.
• Sugar molecules start out lumped together
and gradually move until they are evenly
spread out.
5. Define diffusion.
• Movement of molecules from an area of high
concentration to an area of low concentration.
6. Red blood cells have a salt
concentration of 0.9%
• In a solution of 1.2% salt, they will shrink
because water moves out of the cell.
• In a 0.9% saline solution, they will remain the
same because the two are equal.
• In pure water, they will swell because water
will move into the cell.
7. Define osmosis.
• Diffusion of water molecules.
8. In the diagram, which direction will
the substances move?
• From left to right (high conc. to low conc.)
10. A cell will swell when it is placed in
a __________ solution.
• hypotonic
11. A cell will shrink when placed in a
_____________ solution.
• hypertonic
12. A cell will remain the same when
placed in an ___________ solution.
• isotonic
13. What is the difference between
active and passive transport?
• Active requires energy and moves molecules
against their concentration gradient.
• Passive does not require energy and moves
molecules down their concentration gradient.
14. Proteins that act like selective
passageways in the cell membrane
are known as ___________.
• Channel proteins
15. What kind of molecules can pass
through the cell membrane unaided?
• Small, nonpolar
16. During the egg demo, the egg
gains mass and became swollen. What
is the explanation for this?
• It was placed in a hypotonic solution and
water moved into the egg.
17. What is the energy source for
active transport?
• ATP
18. Molecules that are too large to be
moved through the membrane can be
transported into the cell by _______.
• Endocytosis
19. Ridding the cell of materials by
discharging the materials in vesicles is
called ______________.
Exocytosis
20. Describe the Sodium-Potassium
pump. What type of transport is it?
• A protein in the cell membrane that moves Na
and K ions against their concentration
gradient. It requires ATP, so it is active
transport.
21. Describe the lipid bilayer.
• Drawing on board!
• It is a double layer of phospholipids arranged
tail to tail, making up the cell membrane.
22. Define concentration gradient.
• A difference in concentrations.
23. What is equilibrium?
• Balance
A cell membrane is ______ permeable
because it allows for the passage of
some substances but not others.
• Semi or selectively