Cell And Molecular Biology Concepts And Experiments 7th Edition By Gerald Karp – Test Bank
To Purchase
this Complete Test Bank with Answers Click the link Below
If face any problem or
Further information contact us At tbzuiqe@gmail.com
Sample Questions
Package Title: Test Bank
Course Title: Karp7e
Chapter Number: 4
Question Type: Multiple Choice
1) Which of the following is a function of membranes?
1. a)
compartmentalization
2. b)
selectively permeable barrier
3. c)
mediates intercellular interactions
4. d)
helps cells respond to external stimuli
5. e)
All of these are correct.
Answer: e
Difficulty: Easy
Learning Objective: LO 4.1 Discuss the functions of biological
membranes.
Section Reference: Section 4.1 An Overview of Membrane Functions
2) Which of the following is not a function of membranes?
1. a)
transporting solutes
2. b)
scaffold for biochemical activities
3. c)
energy transduction
4. d)
signal transition
5. e)
signal transduction
Answer: d
Difficulty: Easy
Learning Objective: LO 4.1 Discuss the functions of biological
membranes.
Section Reference: Section 4.1 An Overview of Membrane Functions
3) What evidence convinced Overton that membranes were composed
of lipids?
1. a) He
could see the lipids in the microscope.
2. b)
Membranes were destroyed by enzymes that degraded lipids.
3. c) He
found that more lipid-soluble solutes enter root hair cells faster than polar
solutes.
4. d)
Membranes dissolved in gasoline.
5. e)
Membranes did not dissolve in water.
Answer: c
Difficulty: Medium
Learning Objective: LO 4.2 Describe the important roles of the
membrane during the life cycle of a eukaryotic cell.
Section Reference: Section 4.2 A Brief History of Studies on
Plasma Membrane Structure
4) Gorter and Grendel extracted lipids from human red blood
cells. They calculated the total surface area for these red blood cells and
found it to be 36 µ2. How much surface area would these lipids cover once they
were spread across the surface of water?
1. a) 72
µ2
2. b) 36
µ2
3. c) 18
µ2
4. d)
144 µ2
5. e) 30
µ2
Answer: a
Difficulty: Medium
Learning Objective: LO 4.2 Describe the important roles of the
membrane during the life cycle of a eukaryotic cell.
Section Reference: Section 4.2 A Brief History of Studies on
Plasma Membrane Structure
5) What did Davson and Danielli add to their model of enzyme
structure to explain the passage of polar solutes and ions through the membrane
and to account for their selective permeability?
1. a)
They proposed protein-lined pores.
2. b)
They proposed lipid-lined pores.
3. c)
They proposed carbohydrate-lined pores.
4. d)
They proposed a protein coating on the cytoplasmic surface of the membrane.
5. e)
They proposed a carbohydrate coating on the external surface of the membrane.
Answer: a
Difficulty: Easy
Learning Objective: LO 4.2 Describe the important roles of the
membrane during the life cycle of a eukaryotic cell.
Section Reference: Section 4.2 A Brief History of Studies on
Plasma Membrane Structure
6) What are the building blocks of a phosphoglyceride,
specifically phosphatidic acid?
1. a)
glycerol + 2 phosphate groups + 1 fatty acid
2. b)
glycerol + 1 phosphate group + 2 fatty acids
3. c)
glycerol + 1 phosphate group
4. d)
glycerol + 3 fatty acids
5. e)
glycerol + 1 phosphate group + 3 fatty acids
Answer: b
Difficulty: Easy
Learning Objective: LO 4.3 Describe the basic structure of the
major types of lipids found in cellular membranes.
Section Reference: Section 4.3 The Chemical Composition of
Membranes
7) What word describes a molecule that contains both hydrophilic
and hydrophobic portions?
1. a)
amphoteric
2. b)
ambidextrous
3. c)
amphipathic
4. d)
rings
5. e)
straight
Answer: c
Difficulty: Easy
Learning Objective: LO 4.3 Describe the basic structure of the
major types of lipids found in cellular membranes.
Section Reference: Section 4.3 The Chemical Composition of
Membranes
8) Glycolipids have been shown to play roles in certain disease
states in humans and other mammals. Which of the situations below illustrate
the ways in which this can happen?
1. a)
failure to add a sugar to the glycolipid.
2. b)
inhibition of glycolipid synthesis.
3. c)
they are the site at which bacterial toxins like those that cause botulism and
cholera first bind cells.
4. d)
they are the site at which the influenza virus first binds a cell.
5. e)
All of these are correct.
Answer: e
Difficulty: Medium
Learning Objective: LO 4.3 Describe the basic structure of the
major types of lipids found in cellular membranes.
Section Reference: Section 4.3 The Chemical Composition of
Membranes
9) Why did liposomes not work against diseases as hoped when
they were first tried?
1. a)
They were degraded in the bloodstream.
2. b)
Immune system phagocytes removed them from the bloodstream before they could
exert an effect.
3. c)
They leaked before getting to their target.
4. d)
They were targeted incorrectly.
5. e)
They expanded osmotically and lysed before reaching their target.
Answer: b
Difficulty: Medium
Learning Objective: LO 4.3 Describe the basic structure of the
major types of lipids found in cellular membranes.
Section Reference: Section 4.3 The Chemical Composition of
Membranes
10) How are the new “stealth liposomes” protected from immune system
phagocytes?
1. a)
They are kept cold before use.
2. b)
They are coated with carbohydrates.
3. c)
They are given a synthetic polymer coating that protects them from immune
destruction.
4. d)
They are loaded with radioactive isotopes.
5. e)
They are colored red.
Answer: c
Difficulty: Easy
Learning Objective: LO 4.3 Describe the basic structure of the
major types of lipids found in cellular membranes.
Section Reference: Section 4.3 The Chemical Composition of
Membranes
11) People who have the AB blood type possess ________.
1) an enzyme that adds an N-acetylgalactosamine to the end of
the oligosaccharide chain on RBC membrane glycolipids
2) an enzyme that adds a galactose to the end of the
oligosaccharide chain on RBC membrane glycolipids
3) an enzyme that adds phospholipids to the end of the
oligosaccharide chain on RBC membrane glycolipids
4) no enzymes capable of attaching galactose or
N-acetylgalactosamine to the end of the oligosaccharide chain on RBC membrane
glycolipids
1. a) 1
2. b) 2
3. c) 3
4. d) 4
5. e) 1
and 2
Answer: e
Difficulty: Medium
Learning Objective: LO 4.3 Describe the basic structure of the
major types of lipids found in cellular membranes.
Section Reference: Section 4.3 The Chemical Composition of
Membranes
12) People who have the A blood type possess ________.
1) an enzyme that adds an N-acetylgalactosamine to the end of
the oligosaccharide chain on RBC membrane glycolipids
2) an enzyme that adds a galactose to the end of the
oligosaccharide chain on RBC membrane glycolipids
3) an enzyme that adds phospholipids to the end of the
oligosaccharide chain on RBC membrane glycolipids
4) no enzymes capable of attaching galactose or
N-acetylgalactosamine to the end of the oligosaccharide chain on RBC membrane
glycolipids
1. a) 1
2. b) 2
3. c) 3
4. d) 4
5. e) 1
and 2
Answer: a
Difficulty: Medium
Learning Objective: LO 4.3 Describe the basic structure of the
major types of lipids found in cellular membranes.
Section Reference: Section 4.3 The Chemical Composition of
Membranes
13) People who have the O blood type possess ________.
1) an enzyme that adds an N-acetylgalactosamine to the end of
the oligosaccharide chain on RBC membrane glycolipids
2) an enzyme that adds a galactose to the end of the
oligosaccharide chain on RBC membrane glycolipids
3) an enzyme that adds phospholipids to the end of the
oligosaccharide chain on RBC membrane glycolipids
4) no enzymes capable of attaching galactose or
N-acetylgalactosamine to the end of the oligosaccharide chain on RBC membrane
glycolipids
1. a) 1
2. b) 2
3. c) 3
4. d) 4
5. e) 1
and 2
Answer: d
Difficulty: Medium
Learning Objective: LO 4.3 Describe the basic structure of the
major types of lipids found in cellular membranes.
Section Reference: Section 4.3 The Chemical Composition of
Membranes
14) What kind of membrane protein penetrates into the
hydrophobic part of the lipid bilayer?
1. a)
integral protein
2. b)
lipid-anchored protein
3. c)
peripheral proteins
4. d)
phosphatidylcholine
5. e)
galactocerebroside
Answer: a
Difficulty: Medium
Learning Objective: LO 4.4 Elaborate on the three classes of
membrane proteins.
Section Reference: Section 4.4 The Structure and Functions of
Membrane Proteins
15) What kind of membrane protein is found entirely outside the
bilayer on either the extracellular or cytoplasmic surface? These proteins are
covalently linked to a membrane lipid situated within the bilayer.
1. a)
integral protein
2. b)
lipid-anchored protein
3. c)
peripheral proteins
4. d)
carbohydrate-anchored protein
5. e)
transmembrane
Answer: b
Difficulty: Medium
Learning Objective: LO 4.4 Elaborate on the three classes of
membrane proteins.
Section Reference: Section 4.4 The Structure and Functions of
Membrane Proteins
16) What kind of membrane protein penetrates into the
hydrophobic part of the lipid bilayer?
1. a)
integral protein
2. b)
lipid-anchored protein
3. c)
peripheral proteins
4. d)
transmembrane protein
5. e)
both integral protein and transmembrane protein
Answer: e
Difficulty: Medium
Learning Objective: LO 4.4 Elaborate on the three classes of membrane
proteins.
Section Reference: Section 4.4 The Structure and Functions of
Membrane Proteins
17) What technique allows an investigation of the
microheterogeneity of a membrane so that one can see localized differences in
different parts of the membrane?
1. a)
freeze-denture replication
2. b)
freeze-fracture replication
3. c)
X-ray crystallography
4. d)
circular dichroism
5. e)
tasty-freeze replication
Answer: b
Difficulty: Easy
Learning Objective: LO 4.4 Elaborate on the three classes of
membrane proteins.
Section Reference: Section 4.4 The Structure and Functions of
Membrane Proteins
18) Why are integral membrane proteins difficult to study?
1. a)
They are difficult to isolate in soluble form due to their hydrophobic
transmembrane domains.
2. b) They
are difficult to isolate in soluble form due to their hydrophilic transmembrane
domains.
3. c)
They are so small.
4. d)
They are so large.
5. e)
None of these are correct.
Answer: a
Difficulty: Medium
Learning Objective: LO 4.4 Elaborate on the three classes of
membrane proteins.
Section Reference: Section 4.4 The Structure and Functions of
Membrane Proteins
19) You treat some cells with a proteolytic enzyme that is too
large to penetrate the cell membrane (Set 1). Another group of cells is made
permeable before treatment with the enzyme (Set 2). A third set of cells was
not treated with the enzyme at all (controls). Proteins are then extracted from
the three different sets of cells and applied to an SDS-PAGE gel. Protein W
migrates to the same distance on a gel of proteins from Set 1 and Set 2;
Protein W migrates a shorter distance on gels of proteins extracted from the
control group than on gels of proteins extracted from Set 1 and Set 2 treated
cells. Protein X migrates to the same distance on a gel of proteins from
control cells and the gels of the proteins from Set 1 and Set 2. Protein Y
migrates a longer distance when extracted from Set 1 cells than does protein Y
in the controls; Protein Y moves an even larger distance in the gel of the
extracts from Set 2. Protein Z migrates the same distance on gels of proteins
from the controls and the proteins extracted from Set 1, but it migrates a
longer distance in extracts from Set 2 cells. Which protein is exposed only on
the exterior of the cell?
1. a) Protein
W
2. b)
Protein X
3. c)
Protein Y
4. d)
Protein Z
5. e)
Protein K
Answer: a
Difficulty: Hard
Learning Objective: LO 4.4 Elaborate on the three classes of
membrane proteins.
Section Reference: Section 4.4 The Structure and Functions of
Membrane Proteins
20) Which protein in the Question above is likely to be buried
within the membrane?
1. a)
Protein W
2. b)
Protein X
3. c)
Protein Y
4. d)
Protein Z
5. e)
Protein A
Answer: b
Difficulty: Hard
Learning Objective: LO 4.4 Elaborate on the three classes of membrane
proteins.
Section Reference: Section 4.4 The Structure and Functions of
Membrane Proteins
21) Once the structure of one member of a membrane protein
family has been determined, researchers can usually apply a strategy called
__________ to learn about the structure and activity of other members of the
family. For example, solution of the structure of the bacterial potassium
channel KcsA provided a lot of data that could be applied to the structure and
mechanism of action of the much more complex eukaryotic potassium channels.
1. a)
heterology modeling
2. b)
homology mapping
3. c)
homology modeling
4. d)
protein mapping
5. e)
homologous characterization
Answer: c
Difficulty: Medium
Learning Objective: LO 4.4 Elaborate on the three classes of
membrane proteins.
Section Reference: Section 4.4 The Structure and Functions of
Membrane Proteins
22) On average, how many amino acids engaged in predominantly
hydrophobic a- helices does it take to cross the hydrophobic part of the
membrane?
1. a)
about 10 amino acids
2. b)
about 20 amino acids
3. c) at
least 40 amino acids
4. d)
about 2 – 3 amino acids
5. e)
None of these are correct.
Answer: b
Difficulty: Easy
Learning Objective: LO 4.4 Elaborate on the three classes of
membrane proteins.
Section Reference: Section 4.4 The Structure and Functions of
Membrane Proteins
23) What word below characterizes the amino acids that are found
in an a-helical segment that spans a membrane?
1. a)
exclusively circular
2. b)
predominantly hydrophilic
3. c)
predominantly hydrophobic
4. d)
predominantly antiparallel
5. e)
totally parallel
Answer: c
Difficulty: Easy
Learning Objective: LO 4.4 Elaborate on the three classes of
membrane proteins.
Section Reference: Section 4.4 The Structure and Functions of
Membrane Proteins
24) What technique below is often used to identify transmembrane
segments of integral proteins?
1. a)
Lineweaver-Burk plot
2. b)
Michaelis-Menten plot
3. c)
hydrophilicity plot
4. d)
hydropathy plot
5. e)
titration plot
Answer: d
Difficulty: Easy
Learning Objective: LO 4.4 Elaborate on the three classes of
membrane proteins.
Section Reference: Section 4.4 The Structure and Functions of
Membrane Proteins
25) A procedure in which the gene for an integral membrane
protein is altered in such a way that the spatial relationships between some of
the amino acids in the protein can be revealed is called ________.
1. a)
site-directed mutagenesis
2. b)
site-directed amenuensis
3. c)
hydropathy plots
4. d)
electron paramagnetic resonance (EPR) spectroscopy
5. e)
infrared spectroscopy
Answer: a
Difficulty: Easy
Learning Objective: LO 4.4 Elaborate on the three classes of
membrane proteins.
Section Reference: Section 4.4 The Structure and Functions of
Membrane Proteins
26) Which of the following can be learned from a computer-based
(computational) analysis of the amino acid sequence of a membrane protein,
which can be readily deduced from the nucleotide sequence of its isolated gene?
1. a)
its structure
2. b)
its color
3. c)
its orientation within the lipid bilayer
4. d)
its population in each cell
5. e)
both its structure and its orientation within the lipid bilayer
Answer: e
Difficulty: Medium
Learning Objective: LO 4.4 Elaborate on the three classes of
membrane proteins.
Section Reference: Section 4.4 The Structure and Functions of Membrane
Proteins
27) What amino acid is made to replace another amino acid in
membrane-spanning a-helices by site-directed mutagenesis of the gene coding for
the protein? This is done in order to determine how close together two such
a-helices are in the structure of an integral protein. The amino acid is added
to facilitate the formation of crosslinks between a-helices that are in close
proximity.
1. a)
phenylalanine
2. b)
alanine
3. c)
cysteine
4. d)
methionine
5. e)
proline
Answer: c
Difficulty: Medium
Learning Objective: LO 4.4 Elaborate on the three classes of
membrane proteins.
Section Reference: Section 4.4 The Structure and Functions of
Membrane Proteins
28) What technique can clarify the dynamic events that occur as
a protein functions by introducing into the protein chemical groups (called
nitroxides) that contain an unpaired electron? The properties of these
nitroxides are sensitive to the distance that separates them and the unpaired
electron produces a characteristic spectrum that can be monitored by the
technique in question. The technique yields information about the distance
between selected protein residues.
1. a)
site-directed mutagenesis
2. b)
site-directed amenuensis
3. c)
hydropathy plots
4. d)
electron paramagnetic resonance (EPR) spectroscopy
5. e)
infrared spectroscopy
Answer: d
Difficulty: Easy
Learning Objective: LO 4.4 Elaborate on the three classes of
membrane proteins.
Section Reference: Section 4.4 The Structure and Functions of
Membrane Proteins
29) Which of the following is not a function of peripheral
proteins?
1. a)
mechanical support for membrane
2. b)
enzymes
3. c)
receptors
4. d)
anchor for integral proteins
5. e)
factors that transmit transmembrane signals
Answer: c
Difficulty: Medium
Learning Objective: LO 4.4 Elaborate on the three classes of
membrane proteins.
Section Reference: Section 4.4 The Structure and Functions of
Membrane Proteins
30) What enzyme was instrumental in the discovery of
GPI-anchored proteins? It was found that this enzyme would release certain
membrane proteins from a membrane.
1. a)
phospholipase
2. b)
lipase
3. c)
hydroxyurease
4. d)
protease
5. e)
trypsin
Answer: a
Difficulty: Medium
Learning Objective: LO 4.4 Elaborate on the three classes of
membrane proteins.
Section Reference: Section 4.4 The Structure and Functions of
Membrane Proteins
31) The temperature at which a lipid bilayer shifts from a fluid
state to a crystalline gel is called the _____.
1. a)
transition temperature
2. b)
temperature optimum
3. c)
transition series
4. d) pH
optimum
5. e)
gelation temperature
Answer: a
Difficulty: Easy
Learning Objective: LO 4.5 Explain why and when membrane
fluidity is important to a cell.
Section Reference: Section 4.5 Membrane Lipids and Membrane
Fluidity
32) What directly or indirectly determines the transition
temperature?
1. a)
the ability of lipid molecules to be packed together
2. b)
whether the fatty acid chains of the lipids are saturated or unsaturated
3. c)
the extent to which the fatty acid chains of the lipids contain double bonds
4. d)
the length of the fatty acid chains
5. e)
All of these are correct.
Answer: e
Difficulty: Medium
Learning Objective: LO 4.5 Explain why and when membrane
fluidity is important to a cell.
Section Reference: Section 4.5 Membrane Lipids and Membrane
Fluidity
33) What property of membranes allows interactions to take place
within the membrane, including the assembly of membrane protein clusters at
particular sites and the formation of specialized structures?
1. a)
hydrophobicity
2. b)
hydrophilicity
3. c)
membrane fluidity
4. d)
their amphipathic nature
5. e)
their amphoteric nature
Answer: c
Difficulty: Medium
Learning Objective: LO 4.5 Explain why and when membrane
fluidity is important to a cell.
Section Reference: Section 4.5 Membrane Lipids and Membrane
Fluidity
34) While culturing some cells, you lower the temperature of the
culture. What happens immediately to the membrane fluidity?
1. a)
Nothing happens.
2. b)
The membrane becomes less fluid.
3. c)
The membrane becomes more fluid.
4. d)
The membrane fluidity fluctuates back and forth from high to low.
5. e)
The membrane fluidity fluctuates back and forth from low to high.
Answer: b
Difficulty: Hard
Learning Objective: LO 4.5 Explain why and when membrane
fluidity is important to a cell.
Section Reference: Section 4.5 Membrane Lipids and Membrane
Fluidity
35) Which of the following cell processes depend on the movement
of membrane components and would probably not be possible if membranes were
rigid, nonfluid structures?
1. a)
cell movement
2. b)
cell division
3. c)
formation of intercellular junctions
4. d)
endocytosis
5. e)
All of these are correct.
Answer: e
Difficulty: Easy
Learning Objective: LO 4.5 Explain why and when membrane
fluidity is important to a cell.
Section Reference: Section 4.5 Membrane Lipids and Membrane
Fluidity
36) Which of the following genetic diseases is characterized by
fragile, abnormally shaped erythrocytes and has been traced to mutations in
ankyrin or spectrin?
1. a)
hemophilia
2. b)
sickle cell anemia
3. c)
hemolytic anemias
4. d)
leukemia
5. e)
erythroblastosis
Answer: c
Difficulty: Medium
Learning Objective: LO 4.6 Describe two techniques for measuring
the rates of diffusion of a specific membrane protein.
Section Reference: Section 4.6 The Dynamic Nature of the Plasma
Membrane
37) Hemolytic anemias are characterized by fragile, abnormally
shaped erythrocytes; the disease has been traced to mutations in ________.
1. a)
actin
2. b)
ankyrin
3. c)
hemoglobin
4. d)
spectrin
5. e)
both ankyrin and spectrin
Answer: e
Difficulty: Medium
Learning Objective: LO 4.6 Describe two techniques for measuring
the rates of diffusion of a specific membrane protein.
Section Reference: Section 4.6 The Dynamic Nature of the Plasma
Membrane
38) How was the asymmetry of membrane lipids discovered?
1. a)
The lipid asymmetry was visualized in the electron microscope.
2. b)
The lipid asymmetry was observed with a special stain in the light microscope.
3. c)
Treatment of intact red blood cells with phospholipases.
4. d)
Treatment of intact red blood cells with trypsin.
5. e)
Treatment of liver cells with phospholipases.
Answer: c
Difficulty: Medium
Learning Objective: LO 4.3 Describe the basic structure of the
major types of lipids found in cellular membranes.
Section Reference: Section 4.3 The Chemical Composition of
Membranes
39) Which of the following is not a potential biological role of
the lipid asymmetry of the plasma membrane?
1. a)
The glycolipids in the outer leaflet of the membrane may serve as receptors.
2. b)
The presence of phosphatidylinositol primarily in the inner leaflet is involved
in signal transduction.
3. c)
Maintenance of a charge differential in the two membrane leaflets.
4. d)
Appearance of phosphatidylserine on the outer surface of aging lymphocytes
marks them for destruction by macrophages.
5. e)
Phosphatidylserine on the surface of platelets serves as a signal for blood
solubilization.
Answer: e
Difficulty: Easy
Learning Objective: LO 4.3 Describe the basic structure of the
major types of lipids found in cellular membranes.
Section Reference: Section 4.3 The Chemical Composition of
Membranes
40) Phosphatidylethanolamine is concentrated in the inner
leaflet of the plasma membrane and tends to promote the curvature of the
membrane, which is important in _________.
1. a) membrane
budding
2. b)
membrane fragmentation
3. c)
membrane fusion
4. d)
signal transduction
5. e)
both membrane budding and membrane fusion
Answer: e
Difficulty: Medium
Learning Objective: LO 4.3 Describe the basic structure of the
major types of lipids found in cellular membranes.
Section Reference: Section 4.3 The Chemical Composition of
Membranes
41) When membrane lipids are extracted from cells and used to
prepare artificial lipid bilayers, cholesterol and sphingolipids tend to
self-assemble into ________ that are more gelated and highly ordered than
surrounding regions consisting primarily of _________.
1. a)
macrodomains, phosphoglycerides
2. b)
microdomains, integral proteins
3. c)
microdomains, phosphoglycerides
4. d)
liquid crystals, phosphoglycerides
5. e)
liquid crystals, microdomains
Answer: c
Difficulty: Medium
Learning Objective: LO 4.5 Explain why and when membrane
fluidity is important to a cell.
Section Reference: Section 4.5 Membrane Lipids and Membrane
Fluidity
42) They are more gelated and highly ordered than the
surrounding more fluid and disordered regions in artificial membranes that
consist primarily of phosphoglycerides. They contain higher concentrations of
sphingolipids and cholesterol and certain proteins become concentrated within
them. What are they?
1. a)
lipid islands
2. b)
collections
3. c)
lipid rafts
4. d)
lipid domains
5. e)
dense bilayers
Answer: c
Difficulty: Medium
Learning Objective: LO 4.5 Explain why and when membrane
fluidity is important to a cell.
Section Reference: Section 4.5 Membrane Lipids and Membrane
Fluidity
43) Enzymes that move certain phospholipids between leaflets
have also which of the following properties?
1. a)
Play a role in establishing and maintaining membrane lipid asymmetry
2. b)
Interacts with neighboring epithelial cells, or the basal membrane
3. c)
Blocks post-synaptic membrane
4. d)
Transport proteins
5. e)
All of the above
Answer: a
Difficulty: Easy
Learning Objective: LO 4.6 Describe two techniques for measuring
the rates of diffusion of a specific membrane protein.
Section Reference: Section 4.6 The Dynamic Nature of the Plasma
Membrane
44) You have fused a mouse cell and a human cell and then
treated the cell with specific antibodies that are covalently linked to
fluorescent dyes (antibodies to mouse proteins – green; antibodies to human
proteins – red). What does the cell look like immediately after fusion?
1. a)
The cell is half red and half green.
2. b)
The red and green labels are uniformly distributed across the entire membrane.
3. c)
The red and green labels are distributed in intermingled patches.
4. d)
The cell appears to be yellow in color.
5. e)
The cell appears to be brown in color.
Answer: a
Difficulty: Hard
Learning Objective: LO 4.6 Describe two techniques for measuring
the rates of diffusion of a specific membrane protein.
Section Reference: Section 4.6 The Dynamic Nature of the Plasma
Membrane
45) _________ can be used to trap integral proteins and drag
them through the membrane with a known force, using forces generated by a
focused laser beam. This yields information about the presence of membrane
barriers.
1. a)
FRAP
2. b)
SPT
3. c)
Fluorescence recovery after photobleaching
4. d)
Optical tweezers
5. e)
SDS-PAGE
Answer: d
Difficulty: Easy
Learning Objective: LO 4.6 Describe two techniques for measuring
the rates of diffusion of a specific membrane protein.
Section Reference: Section 4.6 The Dynamic Nature of the Plasma
Membrane
46) Usually, optical tweezers drag integral proteins a limited
distance before they encounter a barrier that causes their release; upon
release, they typically spring backward. What does this suggest?
1. a)
the presence of solid barriers
2. b)
the presence of elastic barriers
3. c)
the attachment of the proteins to the cytoskeleton
4. d)
the attachment of the proteins to the endoplasmic reticulum
5. e)
the presence of rubber in the membrane
Answer: b
Difficulty: Medium
Learning Objective: LO 4.6 Describe two techniques for measuring
the rates of diffusion of a specific membrane protein.
Section Reference: Section 4.6 The Dynamic Nature of the Plasma
Membrane
47) You modify the gene for an integral membrane protein so that
the cytoplasmic portions of the protein are deleted. When the gene is inserted
in cells, what happens to the mobility of this protein in the membrane?
1. a)
They move much greater distances than the intact protein.
2. b)
They move much smaller distances than the intact protein.
3. c)
They do not move at all.
4. d)
They are not inserted into the membrane so nothing can be learned about their
mobility.
5. e)
They flip to the opposite leaflet.
Answer: a
Difficulty: Medium
Learning Objective: LO 4.6 Describe two techniques for measuring
the rates of diffusion of a specific membrane protein.
Section Reference: Section 4.6 The Dynamic Nature of the Plasma
Membrane
48) Integral membrane proteins have been engineered to lack the
portion that normally projects into the extracellular space. When the gene is
inserted in cells, what happens to the mobility of this protein in the
membrane?
1. a)
They move at a much greater rate than the wild type protein.
2. b)
They move at a much smaller rate than the intact protein.
3. c)
They do not move at all.
4. d)
They are not inserted into the membrane so nothing can be learned about their
mobility.
5. e)
They flip to the opposite leaflet.
Answer: a
Difficulty: Medium
Learning Objective: LO 4.6 Describe two techniques for measuring
the rates of diffusion of a specific membrane protein.
Section Reference: Section 4.6 The Dynamic Nature of the Plasma
Membrane
49) What happens to phospholipid mobility when the cell is
treated with agents that disrupt the underlying membrane skeleton?
1. a)
Their mobility is unchanged.
2. b)
Their mobility is increased because the fences that normally restrict their
diffusion are removed.
3. c)
Their mobility is decreased because the fences that normally restrict their
diffusion are removed.
4. d)
Their mobility is increased because the treatment raises the temperature.
5. e)
Their mobility is decreased because the treatment lowers the temperature.
Answer: b
Difficulty: Medium
Learning Objective: LO 4.6 Describe two techniques for measuring
the rates of diffusion of a specific membrane protein.
Section Reference: Section 4.6 The Dynamic Nature of the Plasma
Membrane
50) Why are the proteins being separated on an SDS
polyacrylamide gel attracted equally to the positive electrode?
1. a)
They carry a relatively uniform positive charge distribution
2. b)
They carry a relatively uniform negative charge distribution.
3. c)
They are all the same molecular weight.
4. d)
They are all the same size.
5. e)
They all have the same degree of hydrophobicity.
Answer: b
Difficulty: Medium
Learning Objective: LO 4.6 Describe two techniques for measuring
the rates of diffusion of a specific membrane protein.
Section Reference: Section 4.6 The Dynamic Nature of the Plasma
Membrane
51) Which proteins move the farthest during SDS-polyacrylamide
gel electrophoresis?
1. a)
the largest
2. b)
the smallest
3. c)
the most negative
4. d)
the most positive
5. e)
both the largest and the most negative
Answer: b
Difficulty: Medium
Learning Objective: LO 4.6 Describe two techniques for measuring
the rates of diffusion of a specific membrane protein.
Section Reference: Section 4.6 The Dynamic Nature of the Plasma
Membrane
52) Which protein in the red blood cell membrane appears to be
responsible for the exchange of bicarbonate ions and chloride ions across the
red blood cell membrane?
1. a)
glycophorin A
2. b)
glycophorin D
3. c)
band 3
4. d) glyceraldehyde
3-phosphate
5. e)
alpha-actinin
Answer: c
Difficulty: Easy
Learning Objective: LO 4.6 Describe two techniques for measuring
the rates of diffusion of a specific membrane protein.
Section Reference: Section 4.6 The Dynamic Nature of the Plasma
Membrane
53) Which protein(s) below is(are) thought to be involved in and
influence the stability of red blood cell membranes and the cells themselves by
imparting strength, elasticity, and pliability to the membrane?
1. a)
actin and tropomyosin
2. b) spectrin
3. c)
band 3
4. d)
ankyrin
5. e)
All of these are correct.
Answer: e
Difficulty: Medium
Learning Objective: LO 4.6 Describe two techniques for measuring
the rates of diffusion of a specific membrane protein.
Section Reference: Section 4.6 The Dynamic Nature of the Plasma
Membrane
54) _________ is the movement of a substance from an area of
high concentration to an area of lower concentration.
1. a)
Denaturation
2. b)
Osmosis
3. c)
Diffusion
4. d)
Transport
5. e)
Defusion
Answer: c
Difficulty: Easy
Learning Objective: LO 4.7 Explain how substances move across
the cell membrane.
Section Reference: Section 4.7 The Movement of Substances Across
Cell Membranes
55) In what way can a given solute get through a membrane?
1) The solute can pass through the bilayer.
2) The solute can pass through cholesterol.
3) The solute can pass through an aqueous channel.
4) The solute can pass through a pore.
1. a) 1
2. b) 2
3. c) 3
4. d) 4
5. e) 1,
3 and 4
Answer: e
Difficulty: Easy
Learning Objective: LO 4.7 Explain how substances move across
the cell membrane.
Section Reference: Section 4.7 The Movement of Substances Across
Cell Membranes
56) The movement of water through a semipermeable membrane from
a region of lower solute concentration to a region of higher solute
concentration is called ________.
1. a)
diffusion
2. b)
osmosis
3. c)
denaturation
4. d)
metabolism
5. e)
solubility
Answer: b
Difficulty: Medium
Learning Objective: LO 4.7 Explain how substances move across
the cell membrane.
Section Reference: Section 4.7 The Movement of Substances Across
Cell Membranes
57) A channel that opens in response to changes in ionic charge
across a membrane is called a ________.
1. a)
voltage-gated channel
2. b)
charge-gated channel
3. c)
ligand-gated channel
4. d)
positive-gated channel
5. e)
electric-gated channel
Answer: a
Difficulty: Easy
Learning Objective: LO 4.7 Explain how substances move across
the cell membrane.
Section Reference: Section 4.7 The Movement of Substances Across
Cell Membranes
58) What is thought to be important in maintaining the native
structure of the Kv channel membrane protein and promoting its function as a
voltage-gated channel.
1. a)
negatively charged cholesterol
2. b)
positively charged sphingolipids
3. c)
negatively charged phospholipids
4. d)
positively charged phospholipids
5. e)
negatively charged sphingolipids
Answer: c
Difficulty: Medium
Learning Objective: LO 4.7 Explain how substances move across
the cell membrane.
Section Reference: Section 4.7 The Movement of Substances Across
Cell Membranes
59) A channel that opens in response to the binding of a
specific molecule, which is usually not the solute that passes through the
channel is called a ________.
1. a)
voltage-gated channel
2. b)
charge-gated channel
3. c)
ligand-gated channel
4. d)
positive-gated channel
5. e)
electric-gated channel
Answer: c
Difficulty: Easy
Learning Objective: LO 4.7 Explain how substances move across
the cell membrane.
Section Reference: Section 4.7 The Movement of Substances Across
Cell Membranes
60) Diffusion during which the substance to be transported binds
selectively to a membrane-spanning protein, which helps the process along, is
called ________.
1. a)
osmosis
2. b)
facilitated osmosis
3. c)
simple diffusion
4. d)
facilitated diffusion
5. e)
active transport
Answer: d
Difficulty: Easy
Learning Objective: LO 4.7 Explain how substances move across
the cell membrane.
Section Reference: Section 4.7 The Movement of Substances Across
Cell Membranes
61) An important aspect of transport by facilitated transporters
and pumps is ________.
1. a)
conformational shifts
2. b)
rigidity
3. c)
softness
4. d)
a-helix
5. e)
b-pleated sheet
Answer: a
Difficulty: Medium
Learning Objective: LO 4.7 Explain how substances move across
the cell membrane.
Section Reference: Section 4.7 The Movement of Substances Across
Cell Membranes
62) The sodium-potassium pump makes the cell interior more
______ by pumping ____ sodium ions out of the cell for every ____ potassium
ions pumped in.
1. a)
negative, 3, 2
2. b) negative,
2, 3
3. c)
positive, 3, 2
4. d)
positive, 2, 3
5. e)
negative, 4, 3
Answer: a
Difficulty: Hard
Learning Objective: LO 4.7 Explain how substances move across
the cell membrane.
Section Reference: Section 4.7 The Movement of Substances Across
Cell Membranes
63) What is the distinguishing characteristic of a P-type pump?
1. a) It
must be pumped during the cycle.
2. b) It
must be phosphorylated during the cycle.
3. c) It
must be protonated during the cycle.
4. d) It
must be deprotonated during the cycle.
5. e) It
must be potassiumated during the cycle.
Answer: b
Difficulty: Medium
Learning Objective: LO 4.7 Explain how substances move across
the cell membrane.
Section Reference: Section 4.7 The Movement of Substances Across
Cell Membranes
64) In the Na+/glucose cotransporter, _____ moving down its
gradient drives the transport of _____ against its gradient.
1. a)
Na+ ions, K+ ions
2. b)
Na+ ions, glucose
3. c)
glucose, Na+ ions
4. d)
glucose, K+ ions
5. e) K+
ions, glucose
Answer: b
Difficulty: Easy
Learning Objective: LO 4.7 Explain how substances move across
the cell membrane.
Section Reference: Section 4.7 The Movement of Substances Across
Cell Membranes
Comments
Post a Comment