Core Questions
Cell Membrane and Transport
1. Why are phospholipids ideal for making up the
selectively permeable cell membrane?
A. They repel small ions
B. They react readily with water molecules
C. They form triple layers that insulate the cell
D. They have a nonpolar and polar region
D. They have a nonpolar and polar region
2. A cell begins to swell when placed in an
unknown solution. What can you conclude
about the solution?
A. The solution is isotonic
B. The solution is hypotonic
C. The solution is saturated
D. The solution is hypertonic
B. The solution is hypotonic
3. The movement of molecules against the
concentration gradient requires the use of
energy from what molecule?
A. ATP
B. mRNA
C. Protein
D. Lipid
A. ATP
4. Proteins DO NOT easily pass through the
phospholipid bilayer of cell membranes because
A. The membrane is made of protein
B. They contain nitrogen
C. They are very large molecules
D. They cause digestion of the cell
C. They are very large molecules
5. Once a solute and solvent are evenly
distributed in a solution, they will
A. Stop moving about
B. Move back toward a concentration of the
solvent
C. Continue to move about but with no net
movement to higher concentration
D. Be totally out of equilibrium
C. Continue to move about but with no net
movement to higher concentration
6. Using the above diagram and assuming K+ ions
readily cross the cell membrane, which statement best
describes the movement of the K+ ions.
A. Bottom to top
B. Top to bottom
C. Equally in both directions
D. The cell is already at equilibrium
B. Top to bottom
Use the above diagram to answer the following question:
7. Which component of this plasma membrane contains a
hydrophobic region and acts as the primary barrier to
most foreign substances.
A. Protein
B. Cholesterol
C. Carbohydrate chain
D. Phospholipid bilayer
D. Phospholipid bilayer
8. Which of the following terms includes all of
the others
A. Pinocytosis
B. Endocytosis
C. Active transport
D. Phagocytosis
C. Active transport
9. Compare and contrast active and passive
transport in terms of energy use and
concentration gradient
Active Transport
Passive Transport
Energy
Requires energy
Does not require
energy
Concentration
Gradient
Molecules move
up/against
(low  high)
Molecules move
down/with
(high  low)
10. Differentiate between diffusion and
osmosis by giving an example of each.
Diffusion is the movement of molecules from an
area of high concentration to an area of low
concentration.
EXAMPLE: food coloring spreading in a beaker of
water
Osmosis is a special type of diffusion in which
water is moving across a membrane in order to
balance the concentration of molecules that may
not pass across the membrane themselves.
EXAMPLE: water entering or leaving a piece of
potato submerged in aqueous solution.