Answer Key Study Guide on Cell Transport
1. Label the three images below as isotonic/ hypertonic/ hypotonic (with regard to the
solution the cell is placed in)
Hypertonic
Isotonic
Hypotonic
2. Movement across the cell membrane that does not require energy is called
[passive ] transport.
3. The difference in the concentration of a substance across a space is called a
concentration [gradient ].
4. If there is a concentration gradient, substances will move from an area of high
concentration to an area of [low ] concentration.
5. The cell membrane is [ selectively permeable].
6. [Diffusion ] is the simplest type of passive transport.
7. The diffusion of water through a selectively permeable membrane is called [osmosis].
8. A solution that causes a cell to swell is called a [hypotonic ] solution.
9. The process of taking material into the cell by infolding the cell membrane is called
[endocytosis]
10. In [ facilitated] diffusion, membrane proteins help molecules across the membrane.
11. In diffusion, molecules [spread out]
12. The lipid bilayer describes [the cell membrane]
13. Facilitated diffusion moves substances down their concentration gradient [without]
using the cell's energy.
STUDY GUIDE
1. Label a cell membrane (Hydrophobic tails, Hydrophilic Heads, Phospholipid,
Integral Protein(Channel), Glycolipid, Peripheral Proteins, Glycoprotein),
Cholesterol, Bilayer, Carbohydrate)
Glycolipid
Glycoprotein
Carbohydrate
Phospholipid
Bilayer
Channel Protein
Phospholipid
Peripheral
Protein
Hydrophilic Head
Hydrophobic Tails
Cholesterol
2. What is the phospholipid bilayer? How does the structure of a phospholipid
relate to its function in plasma membranes? Gives the cell membrane flexibility,
allows the cell membrane to control what enters and leaves the cell because of
the hydrophobic tails and hydrophilic heads.
3. Explain what will happen to cells when placed in isotonic, hypertonic, and
hypotonic solutions. Include arrows to show the flow of water
Isotonic
Water moves in and out of cell
Happy animal cell
Hypotonic
Water moves into the cell
Cell swells and may burst
Hypertonic
Water moves out of the cell
Cell shrivels up and dies
4. Know the definition of:
Diffusion
Equilibrium
Osmosis
Isotonic
Hypertonic
Hypotonic
Facilitated diffusion
Endocytosis
Phagocytosis
Pinocytosis
Exocytosis
Challenge Questions
Explain why a salt water fish cannot survive in freshwater. (Use the terms hypotonic,
hypertonic and isotonic to explain.)
Explain, in terms of osmosis, why a raisin placed in a cup of pure water overnight will
puff up (Use the terms hypotonic, hypertonic or isotonic to explain.)
Compare and contrast endocytosis and exocytosis.
How do active transport and facilitate diffusion differ?
COMPARE/CONTRAST
the kinds of transport
Active (ATP)
or
Passive
(KINETIC
ENERGY)
Passive
What does it use
to help:
Membrane
proteins?
Vesicles?
Needs no help
(phospholipids)?
Needs no help
DIFFUSION
Example of
substance(s) that
use this kind of
transport in cells
Small Molecules
Passive
Membrane
Proteins
Passive
Needs no help
Passive
Membrane
Proteins
Active
Membrane
Proteins
Active
Vesicles
Large molecules
(solid)
Active
Vesicles
Large molecules
(liquid)
Active
Vesicles
Large molecules
FACILITATED
DIFFUSION
Molecules the
cell needs but
are too large to
pass through the
membrane
Water
OSMOSIS
FACILITATED
DIFFUSION
(ION CHANNELS)
SODIUM-POTASSIUM
(NA+ -K+) PUMP
(ANIMALS)
ENDOCYTOSIS
(PHAGOCYTOSIS)
ENDOCYTOSIS
(PINOCYTOSIS)
EXOCYTOSIS
Molecules the
cell needs but
are too large to
pass through the
membrane
Sodium and
Potassium