WorksheetsAP Biology Cell Membranes Tuff!
Total questions: 30
Worksheet time: 19mins
Name
Class
Date
1.
Biological membranes are composed primarily of
a)
nucleotides and nucleosides
b)
enzymes, electron acceptors, and electron donors
c)
monosaccharides and diasaccharides
d)
lipids
2.
The compounds in biological membranes that form a barrier to the movement of hydrophilic materials across the membrane are
a)
integral membrane proteins
b)
carbohydrates
c)
lipids
d)
peripheral membrane proteins
3.
In biological membranes, the phospholipids are arranged in a _______, with the_______.
a)
bilayer; fatty acids pointing toward each other
b)
bilayer; fatty acids facing outward
c)
single layer; fatty acids facing the interior of the cell
d)
single layer; phosphorus-containing region facing the interior of the cell
4.
A characteristic of plasma membranes that helps them fuse during vesicle formation and phagocytosis is the
a)
ratio of one protein molecule for every 25 phospholipid molecules
b)
capacity of lipids to associate and maintain a bilayer organization
c)
constant length of the fatty acid chain and the degree of saturation
d)
ability of phospholipid molecules to flip over and trade places with other phospholipid molecules
5.
Which statement about cholesterol molecules is true?
a)
They help hold a membrane together.
b)
They alter the fluidity of the membrane.
c)
They attach to carbohydrates.
d)
They disrupt membrane function.
6.
House plants adapted to indoor temperatures may die if they are left outdoors, because in a cold environment their
a)
DNA cannot function.
b)
membranes lack adequate fluidity.
c)
photosynthesis is impaired.
d)
membranes contain too many unsaturated fatty acids.
7.
In hibernating animals during the winter
a)
signal transduction pathways cease.
b)
membrane lipid composition changes: saturated fatty acids are replaced withunsaturated fatty acids.
c)
membranes toughen as more saturated fatty acids accumulate in them.
d)
there are no changes in lipid composition.
8.
The plasma membranes of winter wheat are able to remain fluid when it is extremely cold by
a)
synthesizing new forms of cholesterol
b)
closing protein channels
c)
decreasing the number of hydrophobic proteins present
d)
replacing saturated fatty acids with unsaturated fatty acids
9.
Which type of membrane protein would likely be most easily removed in a laboratory experiment?
a)
Integral membrane proteins
b)
Channel proteins
c)
Peripheral membrane proteins
d)
Transmembrane proteins
10.
A protein that forms an ion channel through a membrane is most likely
a)
a peripheral membrane protein
b)
a phospholipid
c)
an enzyme.
d)
a transmembrane protein
11.
The LDL receptor is an integral membrane protein that crosses the plasma membrane, with portions of the protein extending both outside and into the interior of the cell. The amino acid side chains (R groups) in the region of the protein that crosses the membrane are most likely
a)
charged
b)
hydrophilic
c)
hydrophobic
d)
carbohydrates
12.
The hydrophilic regions of a membrane protein are most likely
a)
present only in muscle cells
b)
associated with the fatty acid region of the lipids
c)
either on the surface or inserted into the interior of the membrane
d)
exposed on the surface of the membrane
13.
Which statement about peripheral membrane proteins is true?
a)
Their polar regions interact with complementary regions of integral membrane proteins.
b)
They frequently flip from one side of the bilayer to the other.
c)
They have hydrophobic regions within the lipid portion of the bilayer.
d)
They have hydrophilic regions that protrude in aqueous environments on both sides of the membrane.
14.
The two sides of a membrane can be split apart from each other by an experimental technique known as freeze-fracturing. When one side of a freeze-fractured membrane is examined under the electron microscope, the exposed interior of the membrane bilayer appears to be covered with bumps. These bumps are most likely
a)
ice crystals
b)
vesicles
c)
integral membrane proteins.
d)
glycolipids
15.
When a mouse cell and a human cell are fused, the membrane proteins of the two cells become uniformly distributed over the surface of the hybrid cell. This occurs because
a)
many proteins can move around within the bilayer.
b)
all proteins are anchored within the membrane.
c)
all proteins in the plasma membrane are peripheral.
d)
different membranes contain different proteins.
16.
Plasma membranes are relatively impermeable to water-soluble molecules because
a)
the membranes are waxy
b)
water molecules are nonpolar
c)
their bilayer is comprised of phospholipids
d)
they have salt crystals embedded within them
17.
How do the cell membranes of a hibernating animal change in colder temperatures?
a)
They release all of their peripheral membrane proteins
b)
Saturated fatty acids are more tightly packed
c)
Integral membrane proteins increase in number
d)
Unsaturated fatty acids make up more of the lipid composition
18.
Which of the following functions as a recognition site for interactions between cells?
a)
Phospholipids
b)
Cholesterol
c)
Fatty acids
d)
Glycolipids
19.
The rate at which a substance diffuses is not affected by the
a)
phospholipids
b)
temperature of the solution
c)
color of the substance
d)
concentration gradient in the system
20.
The existence of a concentration gradient of glucose across a membrane means that
a)
the glucose molecules are more crowded on one side of the membrane than on the other
b)
there is a high concentration of water on both sides of the membrane
c)
there is a high concentration of glucose on both sides of the membrane
d)
the glucose molecules are chemically bonded more tightly on one side of the membrane than on the other
21.
Which statement about diffusion is false?
a)
Diffusion does not require ATP
b)
Simple diffusion depends upon specific carrier proteins
c)
In diffusion, molecules move from areas of greater concentration to areas of lesser concentration
d)
Diffusion continues until the molecular concentrations are in equilibrium
22.
If a drop of red ink is placed in one end of a shallow pan filled with water, and a drop of green ink is placed in the other end, which of the following will be true at equilibrium?
a)
The red ink will be uniformly distributed in one half of the pan, and the green ink willbe uniformly distributed in the other half of the pan
b)
The concentration of each ink will be higher at one end of the pan than at the other end
c)
Each ink will begin moving down its concentration gradient
d)
The red and green inks will be uniformly distributed throughout the pan
23.
If a hospital patient is mistakenly given an IV of pure water instead of a saline solution that is isotonic to blood, the patient’s red blood cells will
a)
shrink and collapse
b)
release water to the plasma along its concentration gradient
c)
absorb water from the plasma and eventually burst
d)
transport equal amounts of water across the cell membrane in both directions
24.
The difference between osmosis and diffusion is that
a)
diffusion is passive transport, whereas osmosis is active transport
b)
only in diffusion do molecules move from areas of high concentration to areas of low concentration
c)
osmosis is the opposite of diffusion and only involves the movement of water
d)
osmosis refers specifically to the movement of water, whereas diffusion refers to the movement of any type of molecules
25.
Which of the following is not one of the functional roles of membrane proteins?
a)
Allowing movement of molecules that otherwise would be excluded by the lipid components of the membrane
b)
Transferring signals from outside the cell to inside the cell
c)
Facilitating the transport of macromolecules across the membrane
d)
Stabilizing the lipid bilayer
26.
If aquaporins are injected into the membranes of epithelial cells that line blood vessels,
a)
the flow of Na+ through aquaporins will increase
b)
the intracellular concentration of K+ will increase
c)
the membranes will become more permeable to water
d)
the electrical properties of the cells will be altered
27.
Which of the following is the driving force for simple diffusion?
a)
Concentration gradient
b)
ATP hydrolysis
c)
ADP hydrolysis
d)
Phosphorylation
28.
Which of the following is the driving force for facilitated diffusion?
a)
Concentration gradient
b)
ATP hydrolysis
c)
ADP hydrolysis
d)
Phosphorylation
29.
In a hypothetical study, cells are placed in a solution of glucose in which the concentration of glucose is gradually increased. At first, the rate at which glucose enters the cells is found to increase as the concentration of the glucose solution is increased. But when the glucose concentration of the solution is increased above 10 M, the rate no longer increases. Which of the following is the likely mechanism for glucose transport into these cells?
a)
Facilitated diffusion via a carrier protein
b)
Facilitated diffusion via a channel protein
c)
Pinocytosis
d)
Tertiary active transport
30.
If you were designing a drug with an intracellular target, which type of transport system would you want to include in your design as the most efficient way to deliver the drug?
a)
Secondary active transport
b)
Primary active transport
c)
Simple diffusion
d)
Facilitated diffusion via a carrier protein
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