Question 1

A phospholipid molecule has a polar and a nonpolar end.Because of this,water molecules form

Accepted Answer

A)  polar bonds with the nonpolar end of the phospholipid molecule.
B)  polar bonds with the polar end of the phospholipid molecule.
C)  hydrogen bonds with the nonpolar end of the phospholipid molecule.
D)  hydrogen bonds with the polar end of the phospholipid molecule.
E)  covalent bonds with the nonpolar end of the phospholipid moleculE.F) B) and D)
G) B) and E)

Question 2

Membrane proteins are not very soluble in water,because they possess long stretches of non-polar amino acids that

Accepted Answer

A)  are too long to interact with the water molecules.
B)  are hydrophobic.
C)  are transmembranal.
D)  are hydrophilic.
E)  serve as transport channels.F) None of the above
G) B) and D)

Question 3

For the process of diffusion to occur,molecules must

Accepted Answer

A)  move from areas of high concentration to areas of lesser concentration until an equilibrium is reached.
B)  move from areas of low concentration to areas of higher concentration until an equilibrium is reached.
C)  remain stationary until their molecular motion allows for an equilibrium to be reached.
D)  move from areas of high concentration to areas of lesser concentration until facilitated transport can assist the molecular equilibrium.
E)  move from areas of high concentration to areas of lesser concentration until an equilibrium is reached by active transport.F) B) and D)
G) A) and C)

Question 4

The process often thought of as "cell eating" is

Accepted Answer

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

Question 5

Osmosis is the diffusion of water across a membrane in response to the concentration of one or more of the ________.

Accepted Answer

A)  solutes
B)  membranes
C)  compartments
D)  cellsE) All of the above
F) A) and B)

Question 6

The lipid layer that forms the foundation of cell membranes is primarily composed of molecules called ____________.

Accepted Answer

A)  phospholipids
B)  fats
C)  carbohydrates
D)  proteinsE) A) and D)
F) B) and C)

Question 7

Membrane proteins serve many functions.One of the functions is transportation of substances across the membrane.If a cell biologist placed cells into an environment in which a chemical has been added that blocks the function of these transport proteins,which process will be blocked?

Accepted Answer

A)  active transport
B)  osmosis
C)  diffusion
D)  phagocytosis
E)  pinocytosisF) A) and C)
G) C) and D)

Question 8

Incubation of cells at 20 ∘\circ∘ C blocks the release of proteins from the trans-Golgi.Under such conditions,you would expect to see

Accepted Answer

A)  an increase in exocytosis.
B)  a decrease in exocytosis.
C)  an increase in endocytosis.
D)  a decrease in endocytosis. E) A) and B)
F) B) and C)

Question 9

The plasma membrane is a thin sheet of lipid embedded with

Accepted Answer

A)  proteins.
B)  carbohydrates.
C)  polymers.
D)  nucleotides.
E)  sodium and potassium ions.F) B) and E)
G) A) and B)

Question 10

The Fluid Mosaic Model proposed by Singer and Nicolson in 1972 included that

Accepted Answer

A)  the cell membrane was composed of lipids and proteins.
B)  the cell membrane was composed of a phospholipid bilayer between two layers of globular proteins.
C)  the cell membrane was composed of a phospholipid bilayer with globular proteins actually inserted into the bilayer.
D)  the cell membrane was composed of a phospholipid bilayer but the polar ends of the phospholipid molecules were reverseD.E) None of the above
F) A) and B)

Question 11

Cell-walled organisms cannot carry out

Accepted Answer

A)  exocytosis.
B)  active transport.
C)  osmosis.
D)  diffusion.
E)  endocytosis.F) C) and E)
G) A) and E)

Question 12

The type of transport that is specific,which requires specific carrier molecules and energy is

Accepted Answer

A)  exocytosis.
B)  facilitated diffusion.
C)  active transport.
D)  endocytosis.
E)  osmosis.F) B) and D)
G) None of the above

Question 13

Which of the following properties is not true of membrane phospholipids?

Accepted Answer

A)  The hydrophobic tails are oriented towards the interior.
B)  The hydrophilic heads are oriented towards the exterior.
C)  Only the saturated fatty acids are always present.
D)  Once they are incorporated they remain in the membrane permanently.
E)  The bilayers made up of them are randomly interspersed with proteins.F) A) and C)
G) None of the above

Question 14

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)  immunity.F) None of the above
G) A) and B)

Question 15

Which of the following is not a component of an animal cell membrane?

Accepted Answer

A)  phospholipids
B)  polynucleotides
C)  aquaporins
D)  glycolipids
E)  cholesterolF) D) and E)
G) B) and D)

Question 16

If two solutions have unequal concentrations of a solute,the solution with the lower concentration is called

Accepted Answer

A)  isotonic.
B)  hypertonic.
C)  hypotoniC.
D)  hypnotic.
E)  osmosis.F) A) and B)
G) None of the above

Question 17

The type of diffusion that is specific and passive,and which becomes saturated if all of the protein carriers are in use is

Accepted Answer

A)  exocytosis.
B)  facilitated diffusion.
C)  active transport.
D)  endocytosis.
E)  osmosis.F) A) and E)
G) B) and C)

Question 18

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) B) and C)

Question 19

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

Accepted Answer

A)  transport channels
B)  hormones
C)  receptors
D)  enzymes
E)  identity markersF) A) and D)
G) B) and E)

Question 20

While eating lobster for dinner one night you begin thinking about the fact that this type of marine invertebrate is isosmotic with respect to the surrounding seawater.Your friend asks what would happen if the lobster you were eating had not been caught,but instead was moved to a bay with a slightly lower concentration of salt.You reply that in order for the lobster to be isosmotic with respect to new environment,

Accepted Answer

A)  it must move water in to match the solute concentration of its new environment.
B)  it regulates its internal concentration of solutes to match that of its new environment.
C)  it must move water out to match the solute concentration of its new environment.
D)  it moves water in or out and regulates its internal concentration of solutes as needeD.E) C) and D)
F) A) and D)

Exam 5: Membranes

Incubation of cells at 20^$\circ$C blocks the release of proteins from the trans-Golgi.Under such conditions,you would expect to see

Correct Answer
verified

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

Correct Answer
verified

The plasma membrane is a thin sheet of lipid embedded with

Correct Answer
verified

The process often thought of as "cell eating" is

Correct Answer
verified

The Fluid Mosaic Model proposed by Singer and Nicolson in 1972 included that

Correct Answer
verified

If two solutions have unequal concentrations of a solute,the solution with the lower concentration is called

Correct Answer
verified

Membrane proteins serve many functions.One of the functions is transportation of substances across the membrane.If a cell biologist placed cells into an environment in which a chemical has been added that blocks the function of these transport proteins,which process will be blocked?

Correct Answer
verified

Which of the following is not a component of an animal cell membrane?

Correct Answer
verified

For the process of diffusion to occur,molecules must

Correct Answer
verified

The lipid layer that forms the foundation of cell membranes is primarily composed of molecules called ____________.

Correct Answer
verified

The type of transport that is specific,which requires specific carrier molecules and energy is

Correct Answer
verified

Which of the following properties is not true of membrane phospholipids?

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

The type of diffusion that is specific and passive,and which becomes saturated if all of the protein carriers are in use is

Correct Answer
verified

Membrane proteins are not very soluble in water,because they possess long stretches of non-polar amino acids that

Correct Answer
verified

Osmosis is the diffusion of water across a membrane in response to the concentration of one or more of the ________.

Correct Answer
verified

A phospholipid molecule has a polar and a nonpolar end.Because of this,water molecules form

Correct Answer
verified

Correct Answer
verified

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

Correct Answer
verified

Cell-walled organisms cannot carry out

Correct Answer
verified

Exam 5: Membranes

Incubation of cells at 20 ∘\circ∘ C blocks the release of proteins from the trans-Golgi.Under such conditions,you would expect to see

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

The plasma membrane is a thin sheet of lipid embedded with

Correct AnswerverifiedShow Answer

The process often thought of as "cell eating" is

Correct AnswerverifiedShow Answer

The Fluid Mosaic Model proposed by Singer and Nicolson in 1972 included that

Correct AnswerverifiedShow Answer

If two solutions have unequal concentrations of a solute,the solution with the lower concentration is called

Correct AnswerverifiedShow Answer

Membrane proteins serve many functions.One of the functions is transportation of substances across the membrane.If a cell biologist placed cells into an environment in which a chemical has been added that blocks the function of these transport proteins,which process will be blocked?

Correct AnswerverifiedShow Answer

Which of the following is not a component of an animal cell membrane?

Correct AnswerverifiedShow Answer

For the process of diffusion to occur,molecules must

Correct AnswerverifiedShow Answer

The lipid layer that forms the foundation of cell membranes is primarily composed of molecules called ____________.

Correct AnswerverifiedShow Answer

The type of transport that is specific,which requires specific carrier molecules and energy is

Correct AnswerverifiedShow Answer

Which of the following properties is not true of membrane phospholipids?

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

The type of diffusion that is specific and passive,and which becomes saturated if all of the protein carriers are in use is

Correct AnswerverifiedShow Answer

Membrane proteins are not very soluble in water,because they possess long stretches of non-polar amino acids that

Correct AnswerverifiedShow Answer

Osmosis is the diffusion of water across a membrane in response to the concentration of one or more of the ________.

Correct AnswerverifiedShow Answer

A phospholipid molecule has a polar and a nonpolar end.Because of this,water molecules form

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Cell-walled organisms cannot carry out

Correct AnswerverifiedShow Answer

Incubation of cells at 20^$\circ$C blocks the release of proteins from the trans-Golgi.Under such conditions,you would expect to see

Correct Answer
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