Deck 5: Membrane Structure, Transport, and Cell Junctions

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Question
The plasma membrane Na+/K+-ATPase pump

A)is used to generate sodium and potassium gradients across the membrane.
B)is a symporter.
C)is a pump for active transport of K+ out of the cell and Na+ into the cell.
D)is a pump for facilitated diffusion of K+ into the cell and Na+ out of the cell.
E)does not require ATP.
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Question
The movement of sucrose and H+ into the cell by the same membrane protein reflects the actions of what type of transporter?

A)Voltage-gated channel.
B)Mechanosensitive channel.
C)Uniporter.
D)Symporter.
E)Antiporter.
Question
What process best characterizes Ca2+ movement from the cytosol (low Ca2+ concentration)into the endoplasmic reticulum (high Ca2+ concentration)?

A)Calcium movement is spontaneous.
B)Calcium movement involves active transport.
C)Calcium movement occurs by facilitated diffusion using a transporter protein.
D)Calcium movement does not require energy.
E)Calcium movement occurs by passive diffusion.
Question
________ bind two or more ions or molecules and transport them in opposite directions across a membrane.

A)Uniporters
B)Symporters
C)Antiporters
D)Dual transporters
E)Channel pumps
Question
The best way to describe cellular membranes are

A)fluid with lipid rafts.
B)solely composed of lipids.
C)composed of a single layer of amphipathic molecules.
D)selective to the transport of gases and small molecules only.
E)found in eukaryotes,but not prokaryotes.
Question
Following a meal,glucose must move from the gut lumen where there is a high glucose concentration into the intestinal cell where there is a relatively low level of glucose.This movement is called

A)passive diffusion.
B)facilitated diffusion.
C)active transport.
D)endocytosis.
E)exocytosis.
Question
How might a plant cell compensate for the excessive membrane fluidity that occurs during prolonged exposures to elevated temperature?

A)Reduce membrane cholesterol content.
B)Alter the lipid composition to have longer fatty acyl tails and fewer double bonds.
C)Alter the lipid composition to have shorter fatty acyl tails and more double bonds.
D)Alter the lipid composition to have shorter and more unsaturated fatty acyl tails.
E)Reduce cholesterol content and alter the lipid composition to have shorter fatty acyl tails.
Question
The pressure required to stop water from moving across the membrane by osmosis is called

A)transport pressure.
B)crenation pressure.
C)atmospheric pressure.
D)osmotic pressure.
E)mechanical pressurE.
Question
Cellular membranes are mosaic and

A)fluid.
B)rigid.
C)symmetrical.
D)highly permeable to large molecules.
E)polar.
Question
Passive diffusion

A)is the process by which molecules move from an area of low concentration to an area of high concentration.
B)is a spontaneous process.
C)requires the presence of a transmembrane protein.
D)will occur so long as the membrane is freely permeable to the solute.
E)requires energy.
Question
Scientists unearth a Wooly Mammoth from the Siberian Ice Sheath and discover that a eukaryotic "amoeba"-like cell is still alive.Which component of the cell membrane might contribute to maintaining the fluidity of plasma membranes under freezing conditions?

A)Peripheral proteins
B)High levels of long fatty acyl tails within the lipid bilayer
C)High levels of unsaturated fatty acyl tails within the lipid bilayer
D)Absence of cholesterol
E)High levels of saturated fatty acyl tails within the lipid bilayer
Question
What are the two major components of cell membranes?

A)Glycolipids and phospholipids
B)Cholesterol and proteins
C)Phospholipids and carbohydrates
D)Phospholipids and cholesterol
E)Phospholipids and proteins
Question
The release of the protein insulin from pancreatic cells occurs by

A)endocytosis.
B)pinocytosis.
C)phagocytosis.
D)exocytosis.
E)receptor-mediated endocytosis.
Question
An artificial membrane vesicle is mixed with several peripheral membrane proteins and analyzed by freeze-fracture electron microscopy.What will be seen in the resulting image?

A)Bumps will be visible on both layers
B)Bumps will be visible only in the extracellular face (E face)
C)Bumps will be visible in the protoplasmic face (P face)
D)No bumps will be visible in either face
Question
Water diffuses through certain organs such as the kidneys and bladder much faster than would occur by passive diffusion through a lipid bilayer alone.What accounts for this more rapid rate of water transport in these organs?

A)The composition of lipids changes to promote water transport.
B)Presence of aquaporin channels for facilitated diffusion of water.
C)Presence of a water pump.
D)Presence of an ATP-driven enzyme for water transport.
E)The presence of molecules that bind water and change its membrane permeability properties.
Question
Cell surface molecules are labeled with a fluorescent tag and then a portion of them are bleached with a laser beam.What would one observe after the cell is incubated for a few minutes?

A)The bleached molecules would disappear into the cell.
B)The bleached molecules would diffuse laterally through the membrane and intermix with unbleached molecules.
C)The bleached molecules would remain in the spot where bleaching occurred.
D)All the bleached molecules would flip-flop across the cell membrane.
E)The bleached molecules would be released from the cell.
Question
Which membrane component is most important for allowing large,charged molecules to pass through the membrane?

A)Peripheral proteins
B)Cholesterol
C)Glycosylated lipids
D)Transmembrane proteins
E)Carbohydrate channels
Question
In order to study a cell at lower temperatures,a researcher must artificially increase its membrane fluidity.What would be a reasonable strategy for increasing plasma membrane fluidity at low temperatures?

A)Decrease the composition of cholesterol in the plasma membrane
B)Increase the composition of phospholipids with saturated fatty acid chains
C)Decrease the composition of phospholipids with unsaturated fatty acid chains
D)Decrease the length of the phospholipid fatty acyl tail.
E)All of the above strategies are reasonable
Question
Acetylcholine binds this membrane protein,which subsequently opens to allow sodium to enter the cell.Acetylcholine exerts its effect on what type of transport protein?

A)Ligand-gated channel
B)Voltage-gated channel
C)Mechanosensitive-gated channels
D)Uniporter
E)Symporter
Question
Sodium concentrations are higher outside and glucose concentrations are higher inside the cell.Using the same membrane protein for Na+ and glucose transport,what is it called when a Na+ electrochemical gradient is used to drive glucose transport into the cell against its concentration gradient?

A)Primary active transport
B)Secondary active transport
C)Primary facilitated diffusion
D)Secondary facilitated diffusion
E)Passive diffusion
Question
A researcher is studying the integral membrane protein "mysteriase" and chooses to perform an experiment similar to that performed by Frye and Edidin.The researcher fuses a mouse cell expressing mysteriase with a human cell.The fused cell is incubated at 37 \circ C prior to being cooled to 0 \circ C and labeled with a fluorescent antibody against mysteriase.When observed with a fluorescent microscope,mysteriase is observed to remain on one side of the fused cell.What is the most likely explanation for this surprising observation?

A)Mysteriase rigidifies the plasma membrane
B)There is an error in the experimental procedure because this result is impossible
C)Mysteriase is bound to the cytoskeletal filament
D)Mouse cells are less fluid than human cells
E)Mysteriase is a flippase enzyme that enhances lipid flip-flop rather than lipid lateral movement
Question
A protein is tightly associated with the plasma membrane but it can be isolated by treating the membrane with a strong detergent.What type of membrane protein is this?

A)A peripheral membrane protein
B)An integral membrane protein
C)Either an integral or a peripheral membrane protein
D)Neither an integral nor a peripheral membrane protein
Question
Muscular dystrophy is caused by a mutation in the intracellular dystrophin that normally binds to the cytoskeleton.Dystrophin also binds to _______ ,which is found in the plasma membrane of the cell and binds the extra cellular matrix.

A)a gap junction
B)an integrin
C)a cadherin
D)a tight junction
E)an actin filament
Question
Imagine that a cell can be treated with a drug that prevents proteins from undergoing large conformational changes.Which transport proteins would be unaffected by this drug treatment?

A)Na+/K+ ATPase
B)H+/sucrose symporter
C)Fructose uniporter
D)Aquaporin
E)All transport proteins would be affected
Question
A dysfunctional cell lacks a signal peptidase and is unable to cleave the ER signal sequence from proteins translated in the ER.What will be the effect on the cell's proteins?

A)The cell will have no integral membrane proteins
B)All cellular proteins will have an ER signal sequence
C)There will be a common signal sequence at the N-terminus of all integral membrane proteins in the plasma membrane
D)All cellular proteins will become membrane proteins
E)There will be a common signal sequence at the C-terminus of all integral membrane proteins in the nuclear envelope
Question
If contents of the intestines can leak into the blood then ______ must have been damaged.

A)focal adhesions
B)tight junctions
C)desmosomes
D)gap junctions
E)hemidesmosomes
Question
Freeze fracture electron microscopy allows one to observe the two-dimensional cross section of membrane proteins.
Question
These anchorage junctions interact with intermediate filaments and anchor cells to the extracellular matrix.

A)Hemidesmosomes
B)Fibronectin
C)Adherens junctions
D)Desmosomes
E)Focal adhesions
Question
Diffusion is the movement of a molecule from an area of high to low concentration.
Question
The process that most involves the selective uptake of a specific cargo molecule into the cell through receptor binding and aggregation is

A)pinocytosis.
B)receptor-mediated endocytosis.
C)autophagocytosis.
D)phagocytosis.
E)receptor-mediated exocytosis.
Question
Ion gradients across the membrane drive numerous cellular functions.
Question
Osmosis describes the movement of water from an area of high to low solute concentration.
Question
For heart muscles to beat in a coordinated rhythm ions must move from one cell to the next through ______.

A)desmosomes
B)gap junctions
C)focal adhesions
D)hemidesmosomes
E)adherens junctions
Question
If the tight junctions in the intestine were disrupted

A)small molecules would not be able to move into cells lining the intestine.
B)intestinal cells could not attach to integral membrane proteins.
C)intestinal cells could not attach to the extracellular matrix.
D)small molecules would not be exchanged between neighboring intestinal cells.
E)bacteria could move from the intestines to the bloodstream causing an infection.
Question
Na+ ion concentrations are higher outside the cell than inside the cell.What type of transport system is required to move Na+ ions in and out of the cell?

A)Na+ moves into the cell by facilitated diffusion and out of the cell by active transport
B)Na+ moves in and out of the cell by passive diffusion
C)Na+ moves in and out of the cell by active transport
D)Na+ moves into the cell by active transport and out of the cell by facilitated diffusion
E)Na+ moves into the cell by facilitated diffusion and can not move out of the cell
Question
Movement of molecules down their concentration gradient can drive the movement of a different molecule against its concentration gradient.
Question
The best descriptive comparison between hemidesmosomes and desmosomes is

A)hemidesmosomes are anchorage junctions but desmosomes are not.
B)hemidesmosomes are found in plant cells while desmosomes are found in animal cells.
C)both hemidesmosomes and desmosomes associate with integrin,but not cadherin molecules.
D)hemidesmosomes interact with actin filaments while desmosomes interact with intermediate filaments.
E)hemidesmosomes anchor cells to the ECM while desmosomes anchor cells to other cells.
Question
How does a macrophage (immune cell)consume a bacteria?

A)Phagocytosis
B)Endocytosis
C)Exocytosis
D)Receptor-mediated endocytosis
E)Pinocytosis
Question
The presence of integral proteins allows membranes to be selectively permeable to certain molecules.
Question
________ act as rivets anchoring adjacent cells together at spots throughout the cell.

A)Focal adhesions
B)Desmosomes
C)Adherens junctions
D)Hemidesmosomes
E)Fibronectin
Question
A pesticide has been found to have a negative effect on different cell types.In some plants it stops the formation of root nodules and in humans it can stop macrophage from taking up bacteria and generally stops cells from take up protein bound nutrients.The cellular function most likely affected is

A)endocytosis.
B)organogenesis.
C)pinocytosis.
D)exocytosis.
E)phagocytosis.
Question
Gap junctions in animal cells are most similar to ________ in plant cells?

A)tight junctions
B)hemidesmosomes
C)plasmodesmata
D)middle lamella
E)primary cell walls
Question
Signals can be sent from the ECM to the cell through _______.

A)claudins
B)connexins
C)fibronectins
D)cadherins
E)integrins
Question
Unlike animals,plants lack a cell junction where small molecules can move from one cell to another cell.
Question
You have engineered a new membrane protein in your lab that uses energy to transport a toxic solute out of a cell and against its gradient.This protein is therefore most like a

A)receptor.
B)pump.
C)channel.
D)uniporter.
E)transporter.
Question
You inject a dye into a cell and observe that it moves into adjacent cells.This would occur through _____.

A)adherins junctions
B)tight junctions
C)desmosomes
D)plasmodesmata
E)gap junctions
Question
One can inject dyes of different sizes into a liver cell and determine those molecules that can readily pass through gap junctions.What sized molecules can pass through gap junctions?

A)<1,000 Daltons
B)>10,000 Daltons
C)>1,000 Daltons,but <1,500 Daltons
D)>5,000 Daltons,but <10,000 Daltons
E)>1,500 Daltons,but <5,000 Daltons
Question
A person working in your lab creates a synthetic semi-fluid like substance embedded with proteins that transport nutrients and ions.This leads you to believe the substance is most similar to

A)cell membranes.
B)mitochondrial matrix.
C)cytoplasm.
D)smooth ER.
E)rough ER.
Question
A drug company wants to design a medicine that will bind to surface proteins and initiate a conformational change allowing the drug to enter.You suggest the study focus on

A)channels.
B)pumps.
C)transporters.
D)receptors.
Question
Tight junctions contain _______.

A)claudins and integrins
B)cadherins and connexins
C)connexins and claudins
D)cadherins and integrins
E)cadherins and claudins
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Deck 5: Membrane Structure, Transport, and Cell Junctions
1
The plasma membrane Na+/K+-ATPase pump

A)is used to generate sodium and potassium gradients across the membrane.
B)is a symporter.
C)is a pump for active transport of K+ out of the cell and Na+ into the cell.
D)is a pump for facilitated diffusion of K+ into the cell and Na+ out of the cell.
E)does not require ATP.
A
2
The movement of sucrose and H+ into the cell by the same membrane protein reflects the actions of what type of transporter?

A)Voltage-gated channel.
B)Mechanosensitive channel.
C)Uniporter.
D)Symporter.
E)Antiporter.
D
3
What process best characterizes Ca2+ movement from the cytosol (low Ca2+ concentration)into the endoplasmic reticulum (high Ca2+ concentration)?

A)Calcium movement is spontaneous.
B)Calcium movement involves active transport.
C)Calcium movement occurs by facilitated diffusion using a transporter protein.
D)Calcium movement does not require energy.
E)Calcium movement occurs by passive diffusion.
B
4
________ bind two or more ions or molecules and transport them in opposite directions across a membrane.

A)Uniporters
B)Symporters
C)Antiporters
D)Dual transporters
E)Channel pumps
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k this deck
5
The best way to describe cellular membranes are

A)fluid with lipid rafts.
B)solely composed of lipids.
C)composed of a single layer of amphipathic molecules.
D)selective to the transport of gases and small molecules only.
E)found in eukaryotes,but not prokaryotes.
Unlock Deck
Unlock for access to all 50 flashcards in this deck.
Unlock Deck
k this deck
6
Following a meal,glucose must move from the gut lumen where there is a high glucose concentration into the intestinal cell where there is a relatively low level of glucose.This movement is called

A)passive diffusion.
B)facilitated diffusion.
C)active transport.
D)endocytosis.
E)exocytosis.
Unlock Deck
Unlock for access to all 50 flashcards in this deck.
Unlock Deck
k this deck
7
How might a plant cell compensate for the excessive membrane fluidity that occurs during prolonged exposures to elevated temperature?

A)Reduce membrane cholesterol content.
B)Alter the lipid composition to have longer fatty acyl tails and fewer double bonds.
C)Alter the lipid composition to have shorter fatty acyl tails and more double bonds.
D)Alter the lipid composition to have shorter and more unsaturated fatty acyl tails.
E)Reduce cholesterol content and alter the lipid composition to have shorter fatty acyl tails.
Unlock Deck
Unlock for access to all 50 flashcards in this deck.
Unlock Deck
k this deck
8
The pressure required to stop water from moving across the membrane by osmosis is called

A)transport pressure.
B)crenation pressure.
C)atmospheric pressure.
D)osmotic pressure.
E)mechanical pressurE.
Unlock Deck
Unlock for access to all 50 flashcards in this deck.
Unlock Deck
k this deck
9
Cellular membranes are mosaic and

A)fluid.
B)rigid.
C)symmetrical.
D)highly permeable to large molecules.
E)polar.
Unlock Deck
Unlock for access to all 50 flashcards in this deck.
Unlock Deck
k this deck
10
Passive diffusion

A)is the process by which molecules move from an area of low concentration to an area of high concentration.
B)is a spontaneous process.
C)requires the presence of a transmembrane protein.
D)will occur so long as the membrane is freely permeable to the solute.
E)requires energy.
Unlock Deck
Unlock for access to all 50 flashcards in this deck.
Unlock Deck
k this deck
11
Scientists unearth a Wooly Mammoth from the Siberian Ice Sheath and discover that a eukaryotic "amoeba"-like cell is still alive.Which component of the cell membrane might contribute to maintaining the fluidity of plasma membranes under freezing conditions?

A)Peripheral proteins
B)High levels of long fatty acyl tails within the lipid bilayer
C)High levels of unsaturated fatty acyl tails within the lipid bilayer
D)Absence of cholesterol
E)High levels of saturated fatty acyl tails within the lipid bilayer
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Unlock for access to all 50 flashcards in this deck.
Unlock Deck
k this deck
12
What are the two major components of cell membranes?

A)Glycolipids and phospholipids
B)Cholesterol and proteins
C)Phospholipids and carbohydrates
D)Phospholipids and cholesterol
E)Phospholipids and proteins
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13
The release of the protein insulin from pancreatic cells occurs by

A)endocytosis.
B)pinocytosis.
C)phagocytosis.
D)exocytosis.
E)receptor-mediated endocytosis.
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k this deck
14
An artificial membrane vesicle is mixed with several peripheral membrane proteins and analyzed by freeze-fracture electron microscopy.What will be seen in the resulting image?

A)Bumps will be visible on both layers
B)Bumps will be visible only in the extracellular face (E face)
C)Bumps will be visible in the protoplasmic face (P face)
D)No bumps will be visible in either face
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15
Water diffuses through certain organs such as the kidneys and bladder much faster than would occur by passive diffusion through a lipid bilayer alone.What accounts for this more rapid rate of water transport in these organs?

A)The composition of lipids changes to promote water transport.
B)Presence of aquaporin channels for facilitated diffusion of water.
C)Presence of a water pump.
D)Presence of an ATP-driven enzyme for water transport.
E)The presence of molecules that bind water and change its membrane permeability properties.
Unlock Deck
Unlock for access to all 50 flashcards in this deck.
Unlock Deck
k this deck
16
Cell surface molecules are labeled with a fluorescent tag and then a portion of them are bleached with a laser beam.What would one observe after the cell is incubated for a few minutes?

A)The bleached molecules would disappear into the cell.
B)The bleached molecules would diffuse laterally through the membrane and intermix with unbleached molecules.
C)The bleached molecules would remain in the spot where bleaching occurred.
D)All the bleached molecules would flip-flop across the cell membrane.
E)The bleached molecules would be released from the cell.
Unlock Deck
Unlock for access to all 50 flashcards in this deck.
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k this deck
17
Which membrane component is most important for allowing large,charged molecules to pass through the membrane?

A)Peripheral proteins
B)Cholesterol
C)Glycosylated lipids
D)Transmembrane proteins
E)Carbohydrate channels
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Unlock for access to all 50 flashcards in this deck.
Unlock Deck
k this deck
18
In order to study a cell at lower temperatures,a researcher must artificially increase its membrane fluidity.What would be a reasonable strategy for increasing plasma membrane fluidity at low temperatures?

A)Decrease the composition of cholesterol in the plasma membrane
B)Increase the composition of phospholipids with saturated fatty acid chains
C)Decrease the composition of phospholipids with unsaturated fatty acid chains
D)Decrease the length of the phospholipid fatty acyl tail.
E)All of the above strategies are reasonable
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Unlock for access to all 50 flashcards in this deck.
Unlock Deck
k this deck
19
Acetylcholine binds this membrane protein,which subsequently opens to allow sodium to enter the cell.Acetylcholine exerts its effect on what type of transport protein?

A)Ligand-gated channel
B)Voltage-gated channel
C)Mechanosensitive-gated channels
D)Uniporter
E)Symporter
Unlock Deck
Unlock for access to all 50 flashcards in this deck.
Unlock Deck
k this deck
20
Sodium concentrations are higher outside and glucose concentrations are higher inside the cell.Using the same membrane protein for Na+ and glucose transport,what is it called when a Na+ electrochemical gradient is used to drive glucose transport into the cell against its concentration gradient?

A)Primary active transport
B)Secondary active transport
C)Primary facilitated diffusion
D)Secondary facilitated diffusion
E)Passive diffusion
Unlock Deck
Unlock for access to all 50 flashcards in this deck.
Unlock Deck
k this deck
21
A researcher is studying the integral membrane protein "mysteriase" and chooses to perform an experiment similar to that performed by Frye and Edidin.The researcher fuses a mouse cell expressing mysteriase with a human cell.The fused cell is incubated at 37 \circ C prior to being cooled to 0 \circ C and labeled with a fluorescent antibody against mysteriase.When observed with a fluorescent microscope,mysteriase is observed to remain on one side of the fused cell.What is the most likely explanation for this surprising observation?

A)Mysteriase rigidifies the plasma membrane
B)There is an error in the experimental procedure because this result is impossible
C)Mysteriase is bound to the cytoskeletal filament
D)Mouse cells are less fluid than human cells
E)Mysteriase is a flippase enzyme that enhances lipid flip-flop rather than lipid lateral movement
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k this deck
22
A protein is tightly associated with the plasma membrane but it can be isolated by treating the membrane with a strong detergent.What type of membrane protein is this?

A)A peripheral membrane protein
B)An integral membrane protein
C)Either an integral or a peripheral membrane protein
D)Neither an integral nor a peripheral membrane protein
Unlock Deck
Unlock for access to all 50 flashcards in this deck.
Unlock Deck
k this deck
23
Muscular dystrophy is caused by a mutation in the intracellular dystrophin that normally binds to the cytoskeleton.Dystrophin also binds to _______ ,which is found in the plasma membrane of the cell and binds the extra cellular matrix.

A)a gap junction
B)an integrin
C)a cadherin
D)a tight junction
E)an actin filament
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Unlock Deck
k this deck
24
Imagine that a cell can be treated with a drug that prevents proteins from undergoing large conformational changes.Which transport proteins would be unaffected by this drug treatment?

A)Na+/K+ ATPase
B)H+/sucrose symporter
C)Fructose uniporter
D)Aquaporin
E)All transport proteins would be affected
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Unlock for access to all 50 flashcards in this deck.
Unlock Deck
k this deck
25
A dysfunctional cell lacks a signal peptidase and is unable to cleave the ER signal sequence from proteins translated in the ER.What will be the effect on the cell's proteins?

A)The cell will have no integral membrane proteins
B)All cellular proteins will have an ER signal sequence
C)There will be a common signal sequence at the N-terminus of all integral membrane proteins in the plasma membrane
D)All cellular proteins will become membrane proteins
E)There will be a common signal sequence at the C-terminus of all integral membrane proteins in the nuclear envelope
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Unlock Deck
k this deck
26
If contents of the intestines can leak into the blood then ______ must have been damaged.

A)focal adhesions
B)tight junctions
C)desmosomes
D)gap junctions
E)hemidesmosomes
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Unlock for access to all 50 flashcards in this deck.
Unlock Deck
k this deck
27
Freeze fracture electron microscopy allows one to observe the two-dimensional cross section of membrane proteins.
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k this deck
28
These anchorage junctions interact with intermediate filaments and anchor cells to the extracellular matrix.

A)Hemidesmosomes
B)Fibronectin
C)Adherens junctions
D)Desmosomes
E)Focal adhesions
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Unlock Deck
k this deck
29
Diffusion is the movement of a molecule from an area of high to low concentration.
Unlock Deck
Unlock for access to all 50 flashcards in this deck.
Unlock Deck
k this deck
30
The process that most involves the selective uptake of a specific cargo molecule into the cell through receptor binding and aggregation is

A)pinocytosis.
B)receptor-mediated endocytosis.
C)autophagocytosis.
D)phagocytosis.
E)receptor-mediated exocytosis.
Unlock Deck
Unlock for access to all 50 flashcards in this deck.
Unlock Deck
k this deck
31
Ion gradients across the membrane drive numerous cellular functions.
Unlock Deck
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Unlock Deck
k this deck
32
Osmosis describes the movement of water from an area of high to low solute concentration.
Unlock Deck
Unlock for access to all 50 flashcards in this deck.
Unlock Deck
k this deck
33
For heart muscles to beat in a coordinated rhythm ions must move from one cell to the next through ______.

A)desmosomes
B)gap junctions
C)focal adhesions
D)hemidesmosomes
E)adherens junctions
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Unlock Deck
k this deck
34
If the tight junctions in the intestine were disrupted

A)small molecules would not be able to move into cells lining the intestine.
B)intestinal cells could not attach to integral membrane proteins.
C)intestinal cells could not attach to the extracellular matrix.
D)small molecules would not be exchanged between neighboring intestinal cells.
E)bacteria could move from the intestines to the bloodstream causing an infection.
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k this deck
35
Na+ ion concentrations are higher outside the cell than inside the cell.What type of transport system is required to move Na+ ions in and out of the cell?

A)Na+ moves into the cell by facilitated diffusion and out of the cell by active transport
B)Na+ moves in and out of the cell by passive diffusion
C)Na+ moves in and out of the cell by active transport
D)Na+ moves into the cell by active transport and out of the cell by facilitated diffusion
E)Na+ moves into the cell by facilitated diffusion and can not move out of the cell
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36
Movement of molecules down their concentration gradient can drive the movement of a different molecule against its concentration gradient.
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Unlock for access to all 50 flashcards in this deck.
Unlock Deck
k this deck
37
The best descriptive comparison between hemidesmosomes and desmosomes is

A)hemidesmosomes are anchorage junctions but desmosomes are not.
B)hemidesmosomes are found in plant cells while desmosomes are found in animal cells.
C)both hemidesmosomes and desmosomes associate with integrin,but not cadherin molecules.
D)hemidesmosomes interact with actin filaments while desmosomes interact with intermediate filaments.
E)hemidesmosomes anchor cells to the ECM while desmosomes anchor cells to other cells.
Unlock Deck
Unlock for access to all 50 flashcards in this deck.
Unlock Deck
k this deck
38
How does a macrophage (immune cell)consume a bacteria?

A)Phagocytosis
B)Endocytosis
C)Exocytosis
D)Receptor-mediated endocytosis
E)Pinocytosis
Unlock Deck
Unlock for access to all 50 flashcards in this deck.
Unlock Deck
k this deck
39
The presence of integral proteins allows membranes to be selectively permeable to certain molecules.
Unlock Deck
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Unlock Deck
k this deck
40
________ act as rivets anchoring adjacent cells together at spots throughout the cell.

A)Focal adhesions
B)Desmosomes
C)Adherens junctions
D)Hemidesmosomes
E)Fibronectin
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41
A pesticide has been found to have a negative effect on different cell types.In some plants it stops the formation of root nodules and in humans it can stop macrophage from taking up bacteria and generally stops cells from take up protein bound nutrients.The cellular function most likely affected is

A)endocytosis.
B)organogenesis.
C)pinocytosis.
D)exocytosis.
E)phagocytosis.
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42
Gap junctions in animal cells are most similar to ________ in plant cells?

A)tight junctions
B)hemidesmosomes
C)plasmodesmata
D)middle lamella
E)primary cell walls
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43
Signals can be sent from the ECM to the cell through _______.

A)claudins
B)connexins
C)fibronectins
D)cadherins
E)integrins
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44
Unlike animals,plants lack a cell junction where small molecules can move from one cell to another cell.
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45
You have engineered a new membrane protein in your lab that uses energy to transport a toxic solute out of a cell and against its gradient.This protein is therefore most like a

A)receptor.
B)pump.
C)channel.
D)uniporter.
E)transporter.
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46
You inject a dye into a cell and observe that it moves into adjacent cells.This would occur through _____.

A)adherins junctions
B)tight junctions
C)desmosomes
D)plasmodesmata
E)gap junctions
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47
One can inject dyes of different sizes into a liver cell and determine those molecules that can readily pass through gap junctions.What sized molecules can pass through gap junctions?

A)<1,000 Daltons
B)>10,000 Daltons
C)>1,000 Daltons,but <1,500 Daltons
D)>5,000 Daltons,but <10,000 Daltons
E)>1,500 Daltons,but <5,000 Daltons
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48
A person working in your lab creates a synthetic semi-fluid like substance embedded with proteins that transport nutrients and ions.This leads you to believe the substance is most similar to

A)cell membranes.
B)mitochondrial matrix.
C)cytoplasm.
D)smooth ER.
E)rough ER.
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49
A drug company wants to design a medicine that will bind to surface proteins and initiate a conformational change allowing the drug to enter.You suggest the study focus on

A)channels.
B)pumps.
C)transporters.
D)receptors.
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50
Tight junctions contain _______.

A)claudins and integrins
B)cadherins and connexins
C)connexins and claudins
D)cadherins and integrins
E)cadherins and claudins
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