Question 1

Contact with ice numbs a person's fingers because at lower temperatures

Accepted Answer

A)   membrane fluidity is reduced in nerve cells.
B)   no ATP can be produced in the fingers.
C)   protein kinases are activated in the nerves.
D)   membranes in nerve cells unzip.
E)   there are changes in the lipid composition of the membranes in nerve cells.F) A) and E)
G) A) and D)

Question 2

Which transport system can move an ion across the plasma membrane against its concentration gradient without using ATP?

Accepted Answer

A)   Secondary active transport
B)   Primary active transport
C)   Simple diffusion
D)   Facilitated diffusion
E)   Facilitated diffusion via a carrier proteinF) A) and B)
G) C) and D)

Question 3

The hydrophilic regions of a membrane protein are most likely

Accepted Answer

A)   present only in muscle cells.
B)   associated with the fatty acid region of the lipids.
C)   in the interior of the membrane.
D)   exposed on the surface of the membrane.
E)   either on the surface or inserted into the interior of the membrane.F) B) and E)
G) C) and D)

Question 4

When a mouse cell and a human cell are fused,the membrane proteins of the two cells become uniformly distributed over the surface of the hybrid cell.This occurs because

Accepted Answer

A)   many proteins can move around within the bilayer.
B)   all proteins are anchored within the membrane.
C)   proteins are asymmetrically distributed within the membrane.
D)   all proteins in the plasma membrane are peripheral.
E)   different membranes contain different proteins.F) C) and E)
G) B) and E)

Question 5

Which of the following functions as a recognition site for interactions between cells?

Accepted Answer

A)   RNA
B)   Phospholipid
C)   Cholesterol
D)   Fatty acid
E)   GlycolipidF) A) and E)
G) B) and C)

Question 6

Plasma membranes are relatively impermeable to water-soluble molecules because

Accepted Answer

A)   the membranes are waxy.
B)   water molecules are nonpolar.
C)   their bilayer is comprised of phospholipids.
D)   they have salt crystals embedded within them.
E)   large proteins extend through both sides of the membranes.F) C) and E)
G) C) and D)

Question 7

Which statement about diffusion is false?

Accepted Answer

A)   Diffusion does not require ATP.
B)   Diffusion continues until the molecular concentrations are in equilibrium.
C)   In diffusion,molecules move from areas of greater concentration to areas of lesser concentration.
D)   Diffusion is a random process.
E)   Simple diffusion depends upon specific carrier proteins.F) All of the above
G) A) and E)

Question 8

In a hypothetical study,cells are placed in a solution of glucose in which the concentration of glucose is gradually increased.At first,the rate at which glucose enters the cells is found to increase as the concentration of the glucose solution is increased.But when the glucose concentration of the solution is increased above 10 M,the rate no longer increases.Which of the following is the likely mechanism for glucose transport into these cells?

Accepted Answer

A)   Facilitated diffusion via a carrier protein
B)   Facilitated diffusion via a channel protein
C)   Pinocytosis
D)   Tertiary active transport
E)   HydrolysisF) B) and C)
G) A) and E)

Question 9

A protein that forms an ion channel through a membrane is most likely

Accepted Answer

A)   a peripheral membrane protein.
B)   a transmembrane protein.
C)   a phospholipid.
D)   an enzyme.
E)   entirely outside the phospholipid bilayer.F) A) and C)
G) A) and B)

Question 10

Plant cells transport sucrose across the vacuole membrane against its concentration gradient by a process known as

Accepted Answer

A)   simple diffusion.
B)   active transport.
C)   passive transport.
D)   facilitated diffusion.
E)   cellular respiration.F) A) and E)
G) A) and B)

Question 11

The process of osmosis allows water molecules to pass through specialized channels in membranes.Which statement about osmosis is true?

Accepted Answer

A)   Water will move across a membrane to a region with less solute.
B)   Water will move across a membrane to a region with more solute.
C)   The direction of osmosis is temperature dependent.
D)   If the membrane does not allow solutes to pass,water will be equal on both sides.
E)   A higher solute concentration on one side of a membrane indicates a higher water concentration on that side.F) A) and D)
G) B) and C)

Question 12

Which statement about peripheral membrane proteins is true?

Accepted Answer

A)   They have hydrophobic regions within the lipid portion of the bilayer.
B)   They have hydrophilic regions that protrude in aqueous environments on both sides of the membrane.
C)   They frequently flip from one side of the bilayer to the other.
D)   They control the rate of simple diffusion.
E)   Their polar regions interact with complementary regions of integral membrane proteins.F) B) and C)
G) All of the above

Question 13

The rate at which a substance diffuses is not affected by the

Accepted Answer

A)   diameter of the molecules or ions.
B)   temperature of the solution.
C)   color of the substance.
D)   concentration gradient in the system.
E)   Both a and bF) A) and B)
G) B) and D)

Question 14

Which process does not involve the uptake of materials into the cell?

Accepted Answer

A)   Exocytosis
B)   Pinocytosis
C)   Endocytosis
D)   Receptor-mediated endocytosis
E)   PhagocytosisF) A) and E)
G) A) and D)

Question 15

Which molecule has a protein kinase receptor?

Accepted Answer

A)   Insulin
B)   Estrogen
C)   Acetylcholine
D)   Sodium
E)   G proteinF) B) and C)
G) A) and E)

Question 16

The compounds in biological membranes that form a barrier to the movement of hydrophilic materials across the membrane are

Accepted Answer

A)   integral membrane proteins.
B)   carbohydrates.
C)   lipids.
D)   nucleic acids.
E)   peripheral membrane proteins.F) None of the above
G) A) and B)

Question 17

How do the cell membranes of a hibernating animal change in colder temperatures?

Accepted Answer

A)   They release all of their peripheral membrane proteins.
B)   Saturated fatty acids are more tightly packed.
C)   Integral membrane proteins increase in number.
D)   Unsaturated fatty acids make up more of the lipid composition.
E)   Fatty acids with longer tails increase in number.F) B) and E)
G) C) and E)

Question 18

Which of the following represents the correct ordering of the number of molecules that are activated by a single molecule of epinephrine,from highest to lowest?

Accepted Answer

A)   cAMP,phosphorylase kinase,glycogen phosphorylase
B)   Glycogen phosphorylase,phosphorylase kinase,cAMP
C)   cAMP,glycogen phosphorylase,phosphorylase kinase
D)   Glycogen phosphorylase,cAMP,phosphorylase kinase
E)   Phosphorylase kinase,glycogen phosphorylase,cAMPF) A) and E)
G) A) and D)

Question 19

For each molecule of ATP consumed during active transport of sodium and potassium,there is an import of _______ ion(s) and an export of _______ ion(s) .

Accepted Answer

A)   two Na+;three K+
B)   two Na+;one K+
C)   one K+;three Na+
D)   two K+;three Na+
E)   three K+;two Na+F) A) and E)
G) B) and C)

Question 20

A molecule that binds to the particular three-dimensional structure of another molecule's receptor site is known as a(n)

Accepted Answer

A)   responder.
B)   receptor.
C)   ligand.
D)   ion channel.
E)   filament.F) B) and C)
G) B) and E)

Exam 5: Cell Membranes and Signaling

A protein that forms an ion channel through a membrane is most likely

Correct Answer
verified

The process of osmosis allows water molecules to pass through specialized channels in membranes.Which statement about osmosis is true?

Correct Answer
verified

Plasma membranes are relatively impermeable to water-soluble molecules because

Correct Answer
verified

Plant cells transport sucrose across the vacuole membrane against its concentration gradient by a process known as

Correct Answer
verified

The rate at which a substance diffuses is not affected by the

Correct Answer
verified

For each molecule of ATP consumed during active transport of sodium and potassium,there is an import of _ ion(s) and an export of _ ion(s) .

Correct Answer
verified

Correct Answer
verified

Which statement about diffusion is false?

Correct Answer
verified

The compounds in biological membranes that form a barrier to the movement of hydrophilic materials across the membrane are

Correct Answer
verified

A molecule that binds to the particular three-dimensional structure of another molecule's receptor site is known as a(n)

Correct Answer
verified

How do the cell membranes of a hibernating animal change in colder temperatures?

Correct Answer
verified

Which process does not involve the uptake of materials into the cell?

Correct Answer
verified

When a mouse cell and a human cell are fused,the membrane proteins of the two cells become uniformly distributed over the surface of the hybrid cell.This occurs because

Correct Answer
verified

The hydrophilic regions of a membrane protein are most likely

Correct Answer
verified

Contact with ice numbs a person's fingers because at lower temperatures

Correct Answer
verified

Which of the following functions as a recognition site for interactions between cells?

Correct Answer
verified

Which molecule has a protein kinase receptor?

Correct Answer
verified

Which statement about peripheral membrane proteins is true?

Correct Answer
verified

Which of the following represents the correct ordering of the number of molecules that are activated by a single molecule of epinephrine,from highest to lowest?

Correct Answer
verified

Which transport system can move an ion across the plasma membrane against its concentration gradient without using ATP?

Correct Answer
verified

Exam 5: Cell Membranes and Signaling

A protein that forms an ion channel through a membrane is most likely

Correct AnswerverifiedShow Answer

The process of osmosis allows water molecules to pass through specialized channels in membranes.Which statement about osmosis is true?

Correct AnswerverifiedShow Answer

Plasma membranes are relatively impermeable to water-soluble molecules because

Correct AnswerverifiedShow Answer

Plant cells transport sucrose across the vacuole membrane against its concentration gradient by a process known as

Correct AnswerverifiedShow Answer

The rate at which a substance diffuses is not affected by the

Correct AnswerverifiedShow Answer

For each molecule of ATP consumed during active transport of sodium and potassium,there is an import of _______ ion(s) and an export of _______ ion(s) .

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Which statement about diffusion is false?

Correct AnswerverifiedShow Answer

The compounds in biological membranes that form a barrier to the movement of hydrophilic materials across the membrane are

Correct AnswerverifiedShow Answer

A molecule that binds to the particular three-dimensional structure of another molecule's receptor site is known as a(n)

Correct AnswerverifiedShow Answer

How do the cell membranes of a hibernating animal change in colder temperatures?

Correct AnswerverifiedShow Answer

Which process does not involve the uptake of materials into the cell?

Correct AnswerverifiedShow Answer

When a mouse cell and a human cell are fused,the membrane proteins of the two cells become uniformly distributed over the surface of the hybrid cell.This occurs because

Correct AnswerverifiedShow Answer

The hydrophilic regions of a membrane protein are most likely

Correct AnswerverifiedShow Answer

Contact with ice numbs a person's fingers because at lower temperatures

Correct AnswerverifiedShow Answer

Which of the following functions as a recognition site for interactions between cells?

Correct AnswerverifiedShow Answer

Which molecule has a protein kinase receptor?

Correct AnswerverifiedShow Answer

Which statement about peripheral membrane proteins is true?

Correct AnswerverifiedShow Answer

Which of the following represents the correct ordering of the number of molecules that are activated by a single molecule of epinephrine,from highest to lowest?

Correct AnswerverifiedShow Answer

Which transport system can move an ion across the plasma membrane against its concentration gradient without using ATP?

Correct AnswerverifiedShow Answer

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verified

For each molecule of ATP consumed during active transport of sodium and potassium,there is an import of _ ion(s) and an export of _ ion(s) .

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
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Correct Answer
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Correct Answer
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