Question 1

Which protein(s)below is(are)thought to be involved in and influence the stability of red blood cell membranes and the cells themselves by imparting strength,elasticity,and pliability to the membrane?

Accepted Answer

A) actin and tropomyosin 
B) spectrin 
C) band 3 
D) ankyrin 
E) All of these are correct.

Question 2

The rate of nerve impulse conduction in two different nerve cell axons differs.The first cell exhibits a rate of conduction substantially higher (about 20 times faster)than the second cell.Both cells have axons of the same diameter.What is a possible explanation for the difference in nerve conduction rate?

Accepted Answer

The answer of The rate of nerve impulse conduction in...

Question 3

You are exploring a rather inhospitable planet,which has seas that are somewhat hydrophobic in nature.Surprisingly,there are living organisms in the seas whose cytoplasm is hydrophobic to a similar degree.These organisms have membranes made primarily of phospholipids arranged in a bilayer.What is the most probable orientation of these phospholipids?

Accepted Answer

The answer of You are exploring a rather inhospitable planet,which...

Question 4

What is the distinguishing characteristic of a P-type pump?

Accepted Answer

A) It must be pumped during the cycle. 
B) It must be phosphorylated during the cycle. 
C) It must be protonated during the cycle. 
D) It must be deprotonated during the cycle. 
E) It must be potassiumated during the cycle.

Question 5

Where in a myelinated axon are nearly all of the ion channels concentrated?

Accepted Answer

A) the cell body 
B) nodes of Ranvier 
C) dendrites 
D) axon terminals 
E) neuron nucleus

Question 6

How was the asymmetry of membrane lipids discovered?

Accepted Answer

A) The lipid asymmetry was visualized in the electron microscope. 
B) The lipid asymmetry was observed with a special stain in the light microscope. 
C) Treatment of intact red blood cells with phospholipases. 
D) Treatment of intact red blood cells with trypsin. 
E) Treatment of liver cells with phospholipases.

Question 7

What causes the membrane potential to return to the normal negative value after an action potential has occurred?

Accepted Answer

A) opening of a voltage-gated K+ channel 
B) opening of a voltage-gated Na+ channel 
C) closing of a voltage-gated K+ channel 
D) opening of a ligand-gated Na+ channel 
E) opening of a voltage-gated K+ facilitated transporter

Question 8

If Gorter and Grendel,as described in the figure below,extracted lipids from the membranes of red blood cells and determined that they covered 96 mm² of water,what would you estimate as the surface area of the red blood cells from which the lipids were extracted?

Accepted Answer

The answer of If Gorter and Grendel,as described in the...

Question 9

Glycolipids have been shown to play roles in certain disease states in humans and other mammals.Which of the situations below illustrate the ways in which this can happen?

Accepted Answer

A) failure to add a sugar to the glycolipid. 
B) inhibition of glycolipid synthesis. 
C) they are the site at which bacterial toxins like those that cause botulism and cholera first bind cells. 
D) they are the site at which the influenza virus first binds a cell. 
E) All of these are correct.

Question 10

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

Accepted Answer

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

Question 11

They are more gelated and highly ordered than the surrounding more fluid and disordered regions in artificial membranes that consist primarily of phosphoglycerides.They contain higher concentrations of sphingolipids and cholesterol and certain proteins become concentrated within them.What are they?

Accepted Answer

A) lipid islands 
B) collections 
C) lipid rafts 
D) lipid domains 
E) dense bilayers

Question 12

Which protein in the Question above is likely to be buried within the membrane?

Accepted Answer

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

Question 13

What happens after a subthreshold depolarization?

Accepted Answer

A) a full action potential 
B) a partial action potential 
C) no action potential 
D) a proportional action potential 
E) a reversal of the direction of the neural impulse

Question 14

Why did liposomes not work against diseases as hoped when they were first tried?

Accepted Answer

A) They were degraded in the bloodstream. 
B) Immune system phagocytes removed them from the bloodstream before they could exert an effect. 
C) They leaked before getting to their target. 
D) They were targeted incorrectly. 
E) They expanded osmotically and lysed before reaching their target.

Question 15

The majority of alleles responsible for CF in the United States contain the same genetic alteration,designated DF508.What is the significance of this alteration and how does it lead to CF?

Accepted Answer

The answer of The majority of alleles responsible for CF...

Question 16

___________ is a process that strengthens certain synapses by repeated neuron stimulation over a short time period.

Accepted Answer

A) Denturation 
B) Long term potentiation 
C) Short term memory 
D) Temporality 
E) Long term deviation

Question 17

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 18

In the figure below,N- and O-glycosidic linkages are depicted.Why are these linkages called N- and O-glycosidic linkages?

Accepted Answer

The answer of In the figure below,N- and O-glycosidic linkages...

Question 19

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 20

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) phosphatidylcholine 
E) galactocerebroside

Exam 4: The Structure and Function of the Plasma Membrane

Which protein(s) below is(are) thought to be involved in and influence the stability of red blood cell membranes and the cells themselves by imparting strength,elasticity,and pliability to the membrane?

What is the distinguishing characteristic of a P-type pump?

Where in a myelinated axon are nearly all of the ion channels concentrated?

How was the asymmetry of membrane lipids discovered?

What causes the membrane potential to return to the normal negative value after an action potential has occurred?

If Gorter and Grendel,as described in the figure below,extracted lipids from the membranes of red blood cells and determined that they covered 96 mm² of water,what would you estimate as the surface area of the red blood cells from which the lipids were extracted?

Glycolipids have been shown to play roles in certain disease states in humans and other mammals.Which of the situations below illustrate the ways in which this can happen?

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

They are more gelated and highly ordered than the surrounding more fluid and disordered regions in artificial membranes that consist primarily of phosphoglycerides.They contain higher concentrations of sphingolipids and cholesterol and certain proteins become concentrated within them.What are they?

Which protein in the Question above is likely to be buried within the membrane?

What happens after a subthreshold depolarization?

Why did liposomes not work against diseases as hoped when they were first tried?

The majority of alleles responsible for CF in the United States contain the same genetic alteration,designated DF508.What is the significance of this alteration and how does it lead to CF?

___________ is a process that strengthens certain synapses by repeated neuron stimulation over a short time period.

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

In the figure below,N- and O-glycosidic linkages are depicted.Why are these linkages called N- and O-glycosidic linkages?

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?

Exam 4: The Structure and Function of the Plasma Membrane

Which protein(s) below is(are) thought to be involved in and influence the stability of red blood cell membranes and the cells themselves by imparting strength,elasticity,and pliability to the membrane?

What is the distinguishing characteristic of a P-type pump?

Where in a myelinated axon are nearly all of the ion channels concentrated?

How was the asymmetry of membrane lipids discovered?

What causes the membrane potential to return to the normal negative value after an action potential has occurred?

If Gorter and Grendel,as described in the figure below,extracted lipids from the membranes of red blood cells and determined that they covered 96 mm2 of water,what would you estimate as the surface area of the red blood cells from which the lipids were extracted?

Glycolipids have been shown to play roles in certain disease states in humans and other mammals.Which of the situations below illustrate the ways in which this can happen?

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

They are more gelated and highly ordered than the surrounding more fluid and disordered regions in artificial membranes that consist primarily of phosphoglycerides.They contain higher concentrations of sphingolipids and cholesterol and certain proteins become concentrated within them.What are they?

Which protein in the Question above is likely to be buried within the membrane?

What happens after a subthreshold depolarization?

Why did liposomes not work against diseases as hoped when they were first tried?

The majority of alleles responsible for CF in the United States contain the same genetic alteration,designated DF508.What is the significance of this alteration and how does it lead to CF?

___________ is a process that strengthens certain synapses by repeated neuron stimulation over a short time period.

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

In the figure below,N- and O-glycosidic linkages are depicted.Why are these linkages called N- and O-glycosidic linkages?

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?

If Gorter and Grendel,as described in the figure below,extracted lipids from the membranes of red blood cells and determined that they covered 96 mm² of water,what would you estimate as the surface area of the red blood cells from which the lipids were extracted?