Question 1

While culturing some cells, you lower the temperature of the culture. What happens immediately to the membrane fluidity?

Accepted Answer

A) Nothing happens. 
B) The membrane becomes less fluid. 
C) The membrane becomes more fluid. 
D) The membrane fluidity fluctuates back and forth from high to low. 
E) The membrane fluidity fluctuates back and forth from low to high.

Question 2

On average, how many amino acids, forming a hydrophobic $\alpha$-helix, does it take to cross the hydrophobic part of the membrane?

Accepted Answer

A) about 10 amino acids 
B) about 20 amino acids 
C) at least 40 amino acids 
D) about 2-3 amino acids 
E) None of these are correct.

Question 3

You treat some cells with a proteolytic enzyme that is too large to penetrate the cell membrane (Set 1). Another group of cells is made permeable to the enzyme before treatment with the enzyme (Set 2). A third set of cells was not treated with the enzyme at all (controls). Proteins are then extracted from the three different sets of cells and applied to an SDS-PAGE gel. Protein W migrates to the same distance on a gel of proteins from Set 1 and Set 2; Protein W migrates a shorter distance on gels of proteins extracted from the control group than on gels of proteins extracted from Set 1 and Set 2 treated cells. Protein X migrates to the same distance on a gel of proteins from control cells and the gels of the proteins from Set 1 and Set 2. Protein Y migrates a longer distance when extracted from Set 1 cells than does protein Y in the controls; Protein Y moves an even larger distance in the gel of the extracts from Set 2. Protein Z migrates the same distance on gels of proteins from the controls and the proteins extracted from Set 1, but it migrates a longer distance in extracts from Set 2 cells. Which protein is exposed only on the exterior of the cell?

Accepted Answer

A) Protein W 
B) Protein X 
C) Protein Y 
D) Protein Z

Question 4

What kind of membrane protein penetrates into the hydrophobic part of the lipid bilayer?

Accepted Answer

A) integral protein 
B) lipid-anchored protein 
C) peripheral proteins 
D) transmembrane protein 
E) both integral protein and transmembrane protein

Question 5

What kind of membrane protein penetrates into the hydrophobic part of the lipid bilayer?

Accepted Answer

A) integral protein 
B) lipid-anchored protein 
C) peripheral protein 
D) phosphatidylcholine 
E) galactocerebroside

Question 6

You treat some cells with a proteolytic enzyme that is too large to penetrate the cell membrane (Set 1). Another group of cells is made permeable to the enzyme before treatment with the enzyme (Set 2). A third set of cells was not treated with the enzyme at all (controls). Proteins are then extracted from the three different sets of cells and applied to an SDS-PAGE gel. Protein W migrates to the same distance on a gel of proteins from Set 1 and Set 2; Protein W migrates a shorter distance on gels of proteins extracted from the control group than on gels of proteins extracted from Set 1 and Set 2 treated cells. Protein X migrates to the same distance on a gel of proteins from control cells and the gels of the proteins from Set 1 and Set 2. Protein Y migrates a longer distance when extracted from Set 1 cells than does protein Y in the controls; Protein Y moves an even larger distance in the gel of the extracts from Set 2. Protein Z migrates the same distance on gels of proteins from the controls and the proteins extracted from Set 1, but it migrates a longer distance in extracts from Set 2 cells. Which protein is likely to have a cytosolic domain and be exposed only on the interior of the cell?

Accepted Answer

A) Protein W 
B) Protein X 
C) Protein Y 
D) Protein Z

Question 7

What factor(s)directly or indirectly determine the transition temperature? (Select all correct choices)

Accepted Answer

A) the ability of lipid molecules to be packed together 
B) whether the fatty acid chains of the lipids are saturated or unsaturated 
C) the extent to which the fatty acid chains of the lipids contain double bonds 
D) the length of the fatty acid chains

Question 8

_________ is the movement of a substance from an area of high concentration to an area of lower concentration.

Accepted Answer

A) denaturation 
B) osmosis 
C) diffusion 
D) transport 
E) defusion

Question 9

The movement of water through a semipermeable membrane from a region of lower solute concentration to a region of higher solute concentration is called ________.

Accepted Answer

A) diffusion 
B) osmosis 
C) denaturation 
D) metabolism 
E) solubility

Question 10

______influx triggers fusion of synaptic vesicles with the synaptic membranes of the presynaptic cell. This same stimulus also triggers __________, releasing neurotransmitters.

Accepted Answer

A) Ca2+ ion, exocytosis 
B) Ca2+ ion, endocytosis 
C) acetylcholine molecules, exocytosis 
D) acetylcholine molecules, endocytosis 
E) Na+ ion, exocytosis

Question 11

To date, the most successful neurotechnology advances have occurred in _________________.

Accepted Answer

A) restoration of sight 
B) restoration of hearing 
C) restoration of mobility 
D) restoration of balance

Question 12

What are the building blocks of a phosphoglyceride, specifically phosphatidic acid?

Accepted Answer

A) glycerol + 2 phosphate groups + 1 fatty acid 
B) glycerol + 1 phosphate group + 2 fatty acids 
C) glycerol + 1 phosphate group 
D) glycerol + 3 fatty acids 
E) glycerol + 1 phosphate group + 3 fatty acids

Question 13

In plants, the analogous mechanism to action potential propagation in animal neuron axons is _________________________.

Accepted Answer

A) plant cells also possess neurons with elongated axons 
B) movement of an action potential through xylem 
C) movement of an action potential through phloem 
D) saltatory conduction from one leaf to another

Question 14

Why might integral membrane proteins be difficult to study based upon what you know of their amino acid composition?

Accepted Answer

A) They are difficult to isolate in soluble form due to their hydrophobic transmembrane domains. 
B) They are difficult to isolate in soluble form due to their hydrophilic transmembrane domains. 
C) They are too small. 
D) They are too large. 
E) None of these are correct.

Question 15

As an action potential is initiated, the membrane is __________. This is caused by the ________ of ________ ions.

Accepted Answer

A) hyperpolarized, efflux, Na+ 
B) depolarized, influx, Na+ 
C) depolarized, influx, K+ 
D) hyperpolarized, influx, Na+ 
E) depolarized, efflux, Na+

Question 16

Which property of membranes allows interactions like the assembly of membrane protein clusters at particular sites and the formation of specialized structures to take place within the membrane?

Accepted Answer

A) hydrophobicity 
B) hydrophilicity 
C) membrane fluidity 
D) their amphipathic nature 
E) their amphoteric nature

Question 17

Which substance will cross a plasma membrane most effectively?

Accepted Answer

A) Molecule AA with an octanol-water partition coefficient of 5 
B) Molecule AB with an octanol-water partition coefficient of 0.5 
C) Molecule AC with an octanol-water partition coefficient of 50 
D) Molecule AD with an octanol-water partition coefficient of 0.05

Question 18

Impulse propagation by a myelinated axon is called ____________ conduction.

Accepted Answer

A) saltatory 
B) myelinated 
C) rapid fire 
D) jump stop 
E) leap frog

Question 19

People who have the O blood type possess ________.

Accepted Answer

A) an enzyme that adds an N-acetylgalactosamine to the end of the oligosaccharide chain on RBC membrane glycolipids 
B) an enzyme that adds a galactose to the end of the oligosaccharide chain on RBC membrane glycolipids 
C) an enzyme that adds phospholipids to the end of the oligosaccharide chain on RBC membrane glycolipids 
D) no enzymes capable of attaching galactose or N-acetylgalactosamine to the end of the oligosaccharide chain on RBC membrane glycolipids 
E) both an enzyme that adds an N-acetylgalactosamine to the end of the oligosaccharide chain on RBC membrane glycolipids and an enzyme that adds a galactose to the end of the oligosaccharide chain on RBC membrane glycolipids

Question 20

Which of the following is NOT a function of membranes?

Accepted Answer

A) transporting solutes 
B) providing a scaffold for biochemical activities 
C) energy transduction 
D) signal transition 
E) signal transduction

Exam 4: The Structure and Function of the Plasma Membrane

While culturing some cells, you lower the temperature of the culture. What happens immediately to the membrane fluidity?

On average, how many amino acids, forming a hydrophobic $\alpha$ -helix, does it take to cross the hydrophobic part of the membrane?

What kind of membrane protein penetrates into the hydrophobic part of the lipid bilayer?

What kind of membrane protein penetrates into the hydrophobic part of the lipid bilayer?

What factor(s) directly or indirectly determine the transition temperature? (Select all correct choices)

_________ is the movement of a substance from an area of high concentration to an area of lower concentration.

The movement of water through a semipermeable membrane from a region of lower solute concentration to a region of higher solute concentration is called ________.

influx triggers fusion of synaptic vesicles with the synaptic membranes of the presynaptic cell. This same stimulus also triggers ____, releasing neurotransmitters.

To date, the most successful neurotechnology advances have occurred in _________________.

What are the building blocks of a phosphoglyceride, specifically phosphatidic acid?

In plants, the analogous mechanism to action potential propagation in animal neuron axons is _________________________.

Why might integral membrane proteins be difficult to study based upon what you know of their amino acid composition?

As an action potential is initiated, the membrane is __. This is caused by the of ions.

Which property of membranes allows interactions like the assembly of membrane protein clusters at particular sites and the formation of specialized structures to take place within the membrane?

Which substance will cross a plasma membrane most effectively?

Impulse propagation by a myelinated axon is called ____________ conduction.

People who have the O blood type possess ________.

Which of the following is NOT a function of membranes?

Exam 4: The Structure and Function of the Plasma Membrane

While culturing some cells, you lower the temperature of the culture. What happens immediately to the membrane fluidity?

On average, how many amino acids, forming a hydrophobic α\alphaα -helix, does it take to cross the hydrophobic part of the membrane?

What kind of membrane protein penetrates into the hydrophobic part of the lipid bilayer?

What kind of membrane protein penetrates into the hydrophobic part of the lipid bilayer?

What factor(s) directly or indirectly determine the transition temperature? (Select all correct choices)

_________ is the movement of a substance from an area of high concentration to an area of lower concentration.

The movement of water through a semipermeable membrane from a region of lower solute concentration to a region of higher solute concentration is called ________.

______influx triggers fusion of synaptic vesicles with the synaptic membranes of the presynaptic cell. This same stimulus also triggers __________, releasing neurotransmitters.

To date, the most successful neurotechnology advances have occurred in _________________.

What are the building blocks of a phosphoglyceride, specifically phosphatidic acid?

In plants, the analogous mechanism to action potential propagation in animal neuron axons is _________________________.

Why might integral membrane proteins be difficult to study based upon what you know of their amino acid composition?

As an action potential is initiated, the membrane is __________. This is caused by the ________ of ________ ions.

Which property of membranes allows interactions like the assembly of membrane protein clusters at particular sites and the formation of specialized structures to take place within the membrane?

Which substance will cross a plasma membrane most effectively?

Impulse propagation by a myelinated axon is called ____________ conduction.

People who have the O blood type possess ________.

Which of the following is NOT a function of membranes?

On average, how many amino acids, forming a hydrophobic $\alpha$ -helix, does it take to cross the hydrophobic part of the membrane?

influx triggers fusion of synaptic vesicles with the synaptic membranes of the presynaptic cell. This same stimulus also triggers ____, releasing neurotransmitters.

As an action potential is initiated, the membrane is __. This is caused by the of ions.