Question 1

The movement of substances to regions of lower concentration is called

Accepted Answer

A)  active transport.
B)  diffusion.
C)  pinocytosis.
D)  pumping.E) None of the above
F) A) and B)

Question 2

The actual transport of protons by the proton pump is mediated by a transmembrane protein which undergoes a change in its

Accepted Answer

A)  conformation.
B)  amino acid sequence.
C)  net charge.
D)  solubility.E) B) and C)
F) All of the above

Question 3

While water continually orients phospholipids into a lipid bilayer, it does not fix the lipids permanently into position.Thus, the bilayer is considered to be _______.

Accepted Answer

A)  static
B)  fluid
C)  fluctuating
D)  chargedE) All of the above
F) None of the above

Question 4

Which of the following protein classes are not found as membrane proteins?

Accepted Answer

A)  transport channels
B)  hormones
C)  receptors
D)  enzymesE) All of the above
F) A) and C)

Question 5

The rate of diffusion of molecules would be fastest in a cell with an

Accepted Answer

A)  internal concentration of 45 percent and an external concentration of 50 percent in cold temperatures.
B)  internal concentration of 50 percent and an external concentration of 12 percent in cold temperatures.
C)  internal concentration of 50 percent and an external concentration of 12 percent in warm temperatures.
D)  internal concentration of 40 percent and an external concentration of 35 percent in warm temperatures.E) A) and C)
F) B) and C)

Question 6

The fluid nature of the membranes is attributed to a lateral movement of

Accepted Answer

A)  protein channels.
B)  phospholipid molecules.
C)  antigen molecules.
D)  pumps such as the proton pump.E) A) and D)
F) B) and C)

Question 7

In bacteria, fungi, and plants the high internal pressure generated by osmosis is counteracted by the mechanical strength of their

Accepted Answer

A)  plasma membranes.
B)  organelles.
C)  cytoskeletons.
D)  cell walls.E) None of the above
F) All of the above

Question 8

Cholesterol is a structural component of cell membranes.Amount of cholesterol present can affect membrane stability and permeability.What is the role of cholesterol in a membrane?

Accepted Answer

A)  A membrane that needs to be more rigid and more permeable, would have high cholesterol ratios.
B)   A membrane that needs to be rigid, such as a protective barrier, would have low cholesterol ratios.
C)   Membranes with low amounts of cholesterol are very stable and have increased permeability.
D)  Membranes with high amounts of cholesterol are very stable and have decreased permeability.E) B) and C)
F) C) and D)

Question 9

If you were a very thirsty cell, which process would you use to take in some nutrients secreted by one of your neighbors?

Accepted Answer

A)  Phagocytosis
B)  Pinocytosis
C)  Receptor-mediated endocytosis
D)  ExocytosisE) A) and C)
F) None of the above

Question 10

In individuals with normal blood sugar levels, glucose is reabsorbed into the bloodstream in the kidney by members of the GLUT transporter family, which form an aqueous pore across the membrane through which glucose can move passively.As a result, no glucose is excreted in urine.However, in people with untreated diabetes mellitus, blood sugar levels are high and glucose is often present in the urine.What can explain this occurrence?

Accepted Answer

A)  High blood glucose levels reverse the concentration gradient, allowing untransported glucose to be excreted in urine.
B)  High blood glucose levels interfere with the coupled transport of water and glucose, allowing untransported glucose to be excreted in urine.
C)  The GLUT transporters become saturated, allowing untransported glucose to be excreted in urine.
D)  The GLUT transporters cannot hydrolyze ATP quickly enough for ATP to transport the extra glucose, thereby allowing untransported glucose to be excreted in urine.E) None of the above
F) A) and B) C

Question 11

An individual is constipated.They take magnesium salts to help loosen the stool.Why does this work?

Accepted Answer

A)  Water moves from the intestines to the blood because the blood is hypertonic
B)   Water moves from the intestines to the blood because the blood is hypotonic.
C)  Water moves from the blood to the intestines because the blood is hypertonic
D)   Water moves from the blood to the intestines because the blood is hypotonic.E) A) and B)
F) B) and C)

Question 12

Turgor pressure is observed when a plant cells environment is ________________.

Accepted Answer

A)  hypoosmotic
B)  isosmotic
C)  osmosis
D)  hyperosmoticE) C) and D)
F) B) and D) A

Question 13

How can freeze-fracture be used to determine the orientation of a protein in a membrane?

Accepted Answer

A)  Freeze-fracture allows a cell to be cleaved in between the lipid bilayer, splitting the plasma membrane into two layers.
B)  Freeze-fracture allows a cell to be cleaved in such a way as to preserve the embedded proteins.
C)  Freeze-fracture cuts the membrane in protein-sized components for viewing under an electron microscope.D) A) and C)
E) A) and B)

Question 14

Which type of proteins is embedded in the cell membrane in both active transport and facilitated transport?

Accepted Answer

A)  carrier
B)  cytoskeletal
C)  structural
D)  targetedE) B) and C)
F) C) and D)

Question 15

If a cell has a normal osmotic pressure of 4500 mmHg and is placed into a solution with an osmotic pressure of 3500 mmHg, what will happen to the cell?

Accepted Answer

A)  The cell will lose water and its osmotic pressure will decrease.
B)  The cell will gain water and its osmotic pressure will decrease.
C)  The cell will gain water and its osmotic pressure will increase.
D)  The cell will lose water and its osmotic pressure will increase.E) None of the above
F) A) and B)

Question 16

Tetrodotoxin is a potent poison, produced by some newts, pufferfish, and blue-ringed octopus that affects sodium transport involved with the voltage gates in neurons.A friend swimming in the Caribbean is pricked by a pufferfish and gets very sick.The most likely action the poison takes is

Accepted Answer

A)  Mimicking a symporter and allowing sodium to rush out and potassium to rush in.
B)  Mimicking an antiporter and allowing sodium to rush out.
C)  Blocking an antiporter so sodium cannot rush in.
D)  Blocking a symporter and keeping sodium from rushing in.E) All of the above
F) B) and C) C

Question 17

The solution in the container is hypertonic to which egg?

Accepted Answer

A)  Egg 1
B)  Egg 2
C)  Egg 3D) None of the above
E) B) and C)

Question 18

The process often referred to as "cellular eating" is

Accepted Answer

A)  osmosis.
B)  pinocytosis.
C)  phagocytosis.
D)  diffusion.E) B) and C)
F) A) and D)

Question 19

Matt is studying how the protein transferrin enters cells.He examines cells that have taken up transferrin, and finds clathrin-coated vesicles.What mechanism was used to take transferrin into the cell?

Accepted Answer

A)  Phagocytosis
B)  Pinocytosis
C)  Exocytosis
D)  Receptor-mediator endocytosisE) C) and D)
F) A) and B)

Question 20

A dehydrated runner drinks a lot of water after a race.They rehydrate because

Accepted Answer

A)  the stomach is hypotonic compared to the bloodstream.
B)   the bloodstream is hypotonic compared to the stomach.
C)  the stomach and bloodstream are isotonic compared to each other.
D)   water will diffuse from a low to high concentration.E) B) and D)
F) None of the above

Exam 5: Membranes

The movement of substances to regions of lower concentration is called

Correct Answer
verified

The actual transport of protons by the proton pump is mediated by a transmembrane protein which undergoes a change in its

Correct Answer
verified

While water continually orients phospholipids into a lipid bilayer, it does not fix the lipids permanently into position.Thus, the bilayer is considered to be _______.

Correct Answer
verified

Which of the following protein classes are not found as membrane proteins?

Correct Answer
verified

The rate of diffusion of molecules would be fastest in a cell with an

Correct Answer
verified

The fluid nature of the membranes is attributed to a lateral movement of

Correct Answer
verified

In bacteria, fungi, and plants the high internal pressure generated by osmosis is counteracted by the mechanical strength of their

Correct Answer
verified

Cholesterol is a structural component of cell membranes.Amount of cholesterol present can affect membrane stability and permeability.What is the role of cholesterol in a membrane?

Correct Answer
verified

If you were a very thirsty cell, which process would you use to take in some nutrients secreted by one of your neighbors?

Correct Answer
verified

Correct Answer
verified
C

An individual is constipated.They take magnesium salts to help loosen the stool.Why does this work?

Correct Answer
verified

Turgor pressure is observed when a plant cells environment is ________________.

Correct Answer
verified
A

How can freeze-fracture be used to determine the orientation of a protein in a membrane?

Correct Answer
verified

Which type of proteins is embedded in the cell membrane in both active transport and facilitated transport?

Correct Answer
verified

If a cell has a normal osmotic pressure of 4500 mmHg and is placed into a solution with an osmotic pressure of 3500 mmHg, what will happen to the cell?

Correct Answer
verified

Tetrodotoxin is a potent poison, produced by some newts, pufferfish, and blue-ringed octopus that affects sodium transport involved with the voltage gates in neurons.A friend swimming in the Caribbean is pricked by a pufferfish and gets very sick.The most likely action the poison takes is

Correct Answer
verified
C

The solution in the container is hypertonic to which egg?

Correct Answer
verified

The process often referred to as "cellular eating" is

Correct Answer
verified

Matt is studying how the protein transferrin enters cells.He examines cells that have taken up transferrin, and finds clathrin-coated vesicles.What mechanism was used to take transferrin into the cell?

Correct Answer
verified

A dehydrated runner drinks a lot of water after a race.They rehydrate because

Correct Answer
verified

Exam 5: Membranes

The movement of substances to regions of lower concentration is called

Correct AnswerverifiedShow Answer

The actual transport of protons by the proton pump is mediated by a transmembrane protein which undergoes a change in its

Correct AnswerverifiedShow Answer

While water continually orients phospholipids into a lipid bilayer, it does not fix the lipids permanently into position.Thus, the bilayer is considered to be _______.

Correct AnswerverifiedShow Answer

Which of the following protein classes are not found as membrane proteins?

Correct AnswerverifiedShow Answer

The rate of diffusion of molecules would be fastest in a cell with an

Correct AnswerverifiedShow Answer

The fluid nature of the membranes is attributed to a lateral movement of

Correct AnswerverifiedShow Answer

In bacteria, fungi, and plants the high internal pressure generated by osmosis is counteracted by the mechanical strength of their

Correct AnswerverifiedShow Answer

Cholesterol is a structural component of cell membranes.Amount of cholesterol present can affect membrane stability and permeability.What is the role of cholesterol in a membrane?

Correct AnswerverifiedShow Answer

If you were a very thirsty cell, which process would you use to take in some nutrients secreted by one of your neighbors?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedC

An individual is constipated.They take magnesium salts to help loosen the stool.Why does this work?

Correct AnswerverifiedShow Answer

Turgor pressure is observed when a plant cells environment is ________________.

Correct AnswerverifiedA

How can freeze-fracture be used to determine the orientation of a protein in a membrane?

Correct AnswerverifiedShow Answer

Which type of proteins is embedded in the cell membrane in both active transport and facilitated transport?

Correct AnswerverifiedShow Answer

If a cell has a normal osmotic pressure of 4500 mmHg and is placed into a solution with an osmotic pressure of 3500 mmHg, what will happen to the cell?

Correct AnswerverifiedShow Answer

Tetrodotoxin is a potent poison, produced by some newts, pufferfish, and blue-ringed octopus that affects sodium transport involved with the voltage gates in neurons.A friend swimming in the Caribbean is pricked by a pufferfish and gets very sick.The most likely action the poison takes is

Correct AnswerverifiedC

The solution in the container is hypertonic to which egg?

Correct AnswerverifiedShow Answer

The process often referred to as "cellular eating" is

Correct AnswerverifiedShow Answer

Matt is studying how the protein transferrin enters cells.He examines cells that have taken up transferrin, and finds clathrin-coated vesicles.What mechanism was used to take transferrin into the cell?

Correct AnswerverifiedShow Answer

A dehydrated runner drinks a lot of water after a race.They rehydrate because

Correct AnswerverifiedShow Answer

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C

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A

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C

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