Question 1

Steroid hormone receptors in animals tend to be

Accepted Answer

A)  glycolipids rather than protein.
B)  transmembrane proteins with an extracellular steroid binding domain.
C)  transmembrane proteins with an intracellular steroid binding domain.
D)  soluble proteins in the cytoplasm.E) B) and D)
F) A) and B)

Question 2

Figure 5.4
-Five dialysis bags,constructed from a semipermeable membrane that is impermeable to sucrose,were filled with various concentrations of sucrose and then placed in separate beakers containing an initial concentration of 0.6 M sucrose solution.At 10-minute intervals,the bags were massed (weighed) ,and the percent change in mass of each bag was graphed.Figure 5.4 illustrates the change in the mass of the bags over time.Which line or lines in the graph in the figure represent(s) bags that contain a solution that is hypertonic at 50 minutes?

Accepted Answer

A)  A and B
B)  B
C)  C
D)  D
E)  D and EF) D) and E)
G) A) and B) B

Question 3

The electrochemical gradient across a membrane would generally be increased by which of the following membrane proteins?

Accepted Answer

A)  a calcium ion channel
B)  a sucrose-proton cotransporter
C)  a hydrogen ion pump
D)  a sodium ion channelE) B) and C)
F) None of the above

Question 4

Submerging a plant cell in distilled water will result in

Accepted Answer

A)  plasmolysis of the cell.
B)  lysis of the cell membrane.
C)  bursting of the cell.
D)  the cell becoming turgid.
E)  the cell becoming flaccid.F) C) and D)
G) A) and D)

Question 5

Which of the following enzymes adds a phosphate group to target proteins?

Accepted Answer

A)  kinase
B)  phosphatase
C)  G protein-coupled receptor
D)  adenylyl cyclaseE) A) and B)
F) A) and C) A

Question 6

Which of the following molecules are localized on the exterior of a phospholipid bilayer?

Accepted Answer

A)  saturated fatty acids
B)  unsaturated fatty acids
C)  phosphate groups
D)  cholesterolE) B) and C)
F) A) and D)

Question 7

Cystic fibrosis is a genetic disease in humans in which the CFTR protein,which functions as a chloride ion channel,is missing or nonfunctional in cell membranes.The CFTR protein belongs to what category of membrane proteins?

Accepted Answer

A)  gap junctions
B)  carrier proteins
C)  electrogenic ion pumps
D)  cotransporters
E)  hydrophilic channelsF) B) and E)
G) A) and E)

Question 8

The fluid mosaic model of membrane structure suggests that membranes

Accepted Answer

A)  are composed of a fluid bilayer of fatty acids with proteins associated on the outer and inner surfaces.
B)  are composed of protein molecules embedded in a fluid bilayer of phospholipids.
C)  are composed of a single fluid layer of phospholipids and proteins.
D)  are composed of a fluid phospholipid bilayer sandwiched between two layers of hydrophilic proteins.E) A) and D)
F) B) and C)

Question 9

Figure 5.5
-Which of the following types of signaling is represented in Figure 5.5?

Accepted Answer

A)  autocrine
B)  paracrine
C)  hormonal
D)  synapticE) All of the above
F) A) and B)

Question 10

Submerging a red blood cell in distilled water will result in

Accepted Answer

A)  plasmolysis of the cell.
B)  lysis of the cell.
C)  the cell becoming turgid.
D)  the cell becoming flacid.E) B) and D)
F) None of the above

Question 11

The sugars associated with glycoproteins and glycolipids of animal cell membranes

Accepted Answer

A)  serve as an energy source for the cell.
B)  serve as markers that distinguish one cell from another.
C)  decrease membrane fluidity at high temperatures.
D)  maintain membrane fluidity at low temperatures.E) A) and B)
F) None of the above

Question 12

When a neuron responds to a particular neurotransmitter by opening gated ion channels,the neurotransmitter is serving as which part of the signal pathway?

Accepted Answer

A)  receptor
B)  relay molecule
C)  signal molecule
D)  transducer
E)  molecule proteinF) A) and E)
G) A) and D) C

Question 13

A drug designed to inhibit the response of cells to the steroid hormone aldosterone would almost certainly result in which of the following?

Accepted Answer

A)  lower cytoplasmic levels of cAMP
B)  an increase in receptor tyrosine kinase activity
C)  a decrease in transcriptional activity of certain genes
D)  a decrease in G protein activityE) None of the above
F) All of the above

Question 14

At human body temperature (37°C) ,cholesterol in membranes functions to

Accepted Answer

A)  make the membrane less fluid by restricting the movement of phospholipids.
B)  make the membrane more fluid by stimulating the movement of phospholipids.
C)  facilitate cell-cell interactions by binding to receptors on neighboring cells.
D)  make the membrane more fluid by crowding integral membrane proteins into restricted areas.E) None of the above
F) A) and B)

Question 15

What kinds of molecules pass through a cell membrane most easily?

Accepted Answer

A)  large hydrophobic
B)  small hydrophobic
C)  large polar
D)  small ionic
E)  large and hydrophilicF) B) and D)
G) B) and E)

Question 16

Which of the following is a characteristic feature of a carrier protein in a plasma membrane?

Accepted Answer

A)  It is a peripheral membrane protein.
B)  It exhibits a specificity for a particular type of molecule.
C)  It requires the expenditure of cellular energy to function.
D)  It works against a concentration gradient.E) B) and C)
F) A) and C)

Question 17

When biological membranes are frozen and then fractured,they tend to break along the middle of the bilayer.The best explanation for this is that

Accepted Answer

A)  the integral membrane proteins are not strong enough to hold the bilayer together.
B)  water that is present in the middle of the bilayer freezes and is easily fractured.
C)  the hydrophobic interactions between ends of the fatty acid tails of the two phospholipid monolayers are the weakest interactions in the membrane.
D)  the carbon-carbon bonds of the phospholipid tails are easily broken.E) A) and B)
F) A) and C)

Question 18

The phosphate transport system in bacteria imports phosphate into the cell against the phosphate concentration gradient.The energy for phosphate import is provided by a pH gradient across the membrane (lower pH outside the cell than inside the cell) ,rather than by ATP hydrolysis.The bacterial phosphate transport system is an example of

Accepted Answer

A)  passive diffusion.
B)  facilitated diffusion.
C)  active transport.
D)  cotransport.
E)  receptor-mediated endocytosis.F) All of the above
G) A) and E)

Question 19

Which of the following processes includes all the others?

Accepted Answer

A)  osmosis
B)  diffusion of a solute across a membrane
C)  passive transport
D)  transport of an ion down its electrochemical gradientE) C) and D)
F) B) and D)

Question 20

Theoretically,how might researchers disrupt signal transduction pathways as possible treatments for cancer?

Accepted Answer

A)  alter G protein-coupled receptors involved in cell cycle regulation to be active in the absence of their normal signaling molecules
B)  inactivate epinephrine receptors on cancer cells
C)  disrupt the function of protein kinases involved in cell cycle regulation
D)  stimulate production of cAMP in cancer cellsE) C) and D)
F) B) and D)

Exam 5: Membrane Transport and Cell Signaling

Steroid hormone receptors in animals tend to be

Correct Answer
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B

The electrochemical gradient across a membrane would generally be increased by which of the following membrane proteins?

Correct Answer
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Submerging a plant cell in distilled water will result in

Correct Answer
verified

Which of the following enzymes adds a phosphate group to target proteins?

Correct Answer
verified
A

Which of the following molecules are localized on the exterior of a phospholipid bilayer?

Correct Answer
verified

Cystic fibrosis is a genetic disease in humans in which the CFTR protein,which functions as a chloride ion channel,is missing or nonfunctional in cell membranes.The CFTR protein belongs to what category of membrane proteins?

Correct Answer
verified

The fluid mosaic model of membrane structure suggests that membranes

Correct Answer
verified

Figure 5.5 -Which of the following types of signaling is represented in Figure 5.5?

Correct Answer
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Submerging a red blood cell in distilled water will result in

Correct Answer
verified

The sugars associated with glycoproteins and glycolipids of animal cell membranes

Correct Answer
verified

When a neuron responds to a particular neurotransmitter by opening gated ion channels,the neurotransmitter is serving as which part of the signal pathway?

Correct Answer
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C

A drug designed to inhibit the response of cells to the steroid hormone aldosterone would almost certainly result in which of the following?

Correct Answer
verified

At human body temperature (37°C) ,cholesterol in membranes functions to

Correct Answer
verified

What kinds of molecules pass through a cell membrane most easily?

Correct Answer
verified

Which of the following is a characteristic feature of a carrier protein in a plasma membrane?

Correct Answer
verified

When biological membranes are frozen and then fractured,they tend to break along the middle of the bilayer.The best explanation for this is that

Correct Answer
verified

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Which of the following processes includes all the others?

Correct Answer
verified

Theoretically,how might researchers disrupt signal transduction pathways as possible treatments for cancer?

Correct Answer
verified

Exam 5: Membrane Transport and Cell Signaling

Steroid hormone receptors in animals tend to be

Correct AnswerverifiedShow Answer

Correct AnswerverifiedB

The electrochemical gradient across a membrane would generally be increased by which of the following membrane proteins?

Correct AnswerverifiedShow Answer

Submerging a plant cell in distilled water will result in

Correct AnswerverifiedShow Answer

Which of the following enzymes adds a phosphate group to target proteins?

Correct AnswerverifiedA

Which of the following molecules are localized on the exterior of a phospholipid bilayer?

Correct AnswerverifiedShow Answer

Cystic fibrosis is a genetic disease in humans in which the CFTR protein,which functions as a chloride ion channel,is missing or nonfunctional in cell membranes.The CFTR protein belongs to what category of membrane proteins?

Correct AnswerverifiedShow Answer

The fluid mosaic model of membrane structure suggests that membranes

Correct AnswerverifiedShow Answer

Figure 5.5 -Which of the following types of signaling is represented in Figure 5.5?

Correct AnswerverifiedShow Answer

Submerging a red blood cell in distilled water will result in

Correct AnswerverifiedShow Answer

The sugars associated with glycoproteins and glycolipids of animal cell membranes

Correct AnswerverifiedShow Answer

When a neuron responds to a particular neurotransmitter by opening gated ion channels,the neurotransmitter is serving as which part of the signal pathway?

Correct AnswerverifiedC

A drug designed to inhibit the response of cells to the steroid hormone aldosterone would almost certainly result in which of the following?

Correct AnswerverifiedShow Answer

At human body temperature (37°C) ,cholesterol in membranes functions to

Correct AnswerverifiedShow Answer

What kinds of molecules pass through a cell membrane most easily?

Correct AnswerverifiedShow Answer

Which of the following is a characteristic feature of a carrier protein in a plasma membrane?

Correct AnswerverifiedShow Answer

When biological membranes are frozen and then fractured,they tend to break along the middle of the bilayer.The best explanation for this is that

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Which of the following processes includes all the others?

Correct AnswerverifiedShow Answer

Theoretically,how might researchers disrupt signal transduction pathways as possible treatments for cancer?

Correct AnswerverifiedShow Answer

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B

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A

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C

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