Question 1

Cells are infected with a virus carrying a temperature-sensitive mutant VSVG gene that encodes a protein that cannot leave the ER of infected cells grown at restrictive temperatures.Thus,at higher temperatures,______________.

Accepted Answer

A)  VSVG protein heads immediately for the Golgi complex.
B)  VSVG protein cannot leave the ER.
C)  VSVG protein leaves the ER immediately.
D)  All of the manufactured VSVG protein leaves the ER synchronously.
E)  VSVG protein is degraded rapidly and never passes to the Golgi complex.

Question 2

What removes the stroma-targeting domain and where does the removal occur?

Accepted Answer

A)  a processing peptide synthase,stroma
B)  a processing peptidase,stroma
C)  a processing peptidase,thylakoid membrane
D)  a processing peptidase,thylakoid lumen
E)  a stromase,stroma

Question 3

What are the functions of housekeeping receptors in the endocytic pathway? What is the function of signaling receptors in the endocytic pathway? How do the fates of housekeeping and signaling receptors generally differ?

Accepted Answer

Housekeeping receptors in the endocytic ...

Question 4

When Rabs have bound to GTP,what do they do?

Accepted Answer

A)  They fuse membranes directly.
B)  They pass through the membrane.
C)  They recruit specific cytosolic tethering proteins to specific membrane surfaces.
D)  They denature specific membrane proteins.
E)  They fuse to the nuclear membrane.

Question 5

What enzyme transfers a block of sugars to asparagine residues of a polypeptide as it enters the RER?

Accepted Answer

A)  glycosyltransferase
B)  acid phosphatase
C)  oligosaccharyltransferase
D)  cellulose
E)  glycolase

Question 6

Which endosomes are typically located in the more interior part of the cell,near the nucleus?

Accepted Answer

A)  late endosomes
B)  early endosomes
C)  medial lysosomes
D)  medial endosomes
E)  intellosomes

Question 7

How and where is the asymmetry of the phospholipid bilayers initially established?

Accepted Answer

A)  It is initially established in the Golgi complex during lipid and protein modification.
B)  It is initially established in the ER during lipid and protein synthesis.
C)  It is initially established in the secretory vesicles during lipid and protein modification
D)  It is initially established in the mitochondria by random insertion into the membranes.
E)  All of these are correct.

Question 8

Which part of the Golgi complex is thought to function primarily as a sorting station that distinguishes between proteins to be shipped back to the ER and those that are allowed to proceed to the next Golgi station?

Accepted Answer

A)  the cis cisternae
B)  the CGN
C)  the medial cisternae
D)  the trans cisternae
E)  the trans-Golgi network

Question 9

What is the primary adaptor protein of the COPII coat that interacts specifically with the ER export signals in the cytosolic tails of membrane proteins that are destined to traffic on to the Golgi complex?

Accepted Answer

A)  ARF1
B)  Sec23
C)  Sec24
D)  Sec31
E)  Sec13

Question 10

The accumulation of misfolded proteins in the ER is a potentially lethal situation and thus causes the triggering of what process?

Accepted Answer

A)  the unfolded protein response (UPR) 
B)  the posttranscriptional response
C)  the polysomal response
D)  the proteasomal response
E)  the intracellular protein response

Question 11

The two separate (basic) categories of uptake of extracellular materials into cytoplasmic vesicles are ______ and ______.

Accepted Answer

A)  phagocytosis,exocytosis
B)  pinocytosis,exocytosis
C)  phagocytosis,endocytosis
D)  pinocytosis,endocytosis
E)  exocytosis,endocytosis

Question 12

What are the differences between early and late endosomes?

Accepted Answer

A)  Early endosomes exchange their Rab5 proteins for Rab7 proteins as they transform into late endosomes.
B)  Late endosomes have a population of vesicles crowding their interior; early endosomes do not.
C)  Late endosomes exhibit a lower pH than early endosomes.
D)  In late endosomes,the outer boundary membrane has budded inward on its lumenal surface creating a group of vesicles.
E)  All of these are correct.

Question 13

What allows the interface between the Sec13-Sec31 subunits to form cages of varying diameter,thus accommodating vesicles of varying size?

Accepted Answer

A)  a degree of flexibility built into the interface between the Sec13-Sec31 subunits
B)  a degree of rigidity built into the interface between the Sec13-Sec31 subunits
C)  a degree of extensibility built into the interface between the Sec13-Sec31 subunits
D)  a protein between Sec13 and Sec31 that allows free rotation
E)  Sec24,which provides a cushion between the Sec13 and Sec31 subunits

Question 14

Cells are infected with a vesicular stomatitis virus (VSV) strain in which a viral gene (VSVG) is fused to the green fluorescent protein gene.When the chimeric protein is synthesized,what pathway does it follow from synthesis until it leaves the cell?

Accepted Answer

A)  RER,Golgi complex,plasma membrane,viral envelopes
B)  RER,Golgi complex,viral envelopes,plasma membrane
C)  Golgi complex,RER,plasma membrane,viral envelopes
D)  RER,Golgi complex,mitochondria,plasma membrane,viral envelopes
E)  RER,mitochondria,Golgi complex,plasma membrane,viral envelopes

Question 15

You wish to target a purified enzyme to the lysosomes of macrophages.How might you accomplish this?

Accepted Answer

If you treat the oligosaccharides of the...

Question 16

What does the conformation-sensing enzyme UGGT do if it binds to a misfolded or incompletely folded glycoprotein?

Accepted Answer

A)  It degrades the oligosaccharide chain.
B)  It adds a single mannose back to one of the glucose residues at the exposed end of the recently trimmed oligosaccharide.
C)  It adds a single glucose back to one of the mannose residues at the exposed end of the recently trimmed oligosaccharide.
D)  It degrades the protein.
E)  It refolds the protein on its own.

Question 17

What is the general name for a molecule that physically links two different types of materials?

Accepted Answer

A)  enzymes
B)  adaptors
C)  structural proteins
D)  receptors
E)  polynucleotides

Question 18

What is thought to direct the movement of vesicles through the cytoplasm to their final destination?

Accepted Answer

A)  microfilaments
B)  microtubules
C)  intermediate filaments
D)  collagen
E)  keratin

Question 19

A scientist isolates two specific mRNAs.One codes for the enzyme fowlase,an enzyme that is involved in digestion in chickadees; the other codes for the quail enzyme quailase that is involved in cellular carbohydrate metabolism.Both mRNAs are placed in a test tube with RER vesicles stripped of their ribosomes,free ribosomes and precursors for protein synthesis.When the protein synthesis reaction is complete,fowlase is found inside the vesicles; quailase is found in the liquid portion of the test tube outside the vesicles.What can one conclude about the two proteins?

Accepted Answer

Fowlase is a secretory protein...

Question 20

What is responsible for degrading misfolded proteins in the cytoplasm?

Accepted Answer

A)  polysomes
B)  polyribosomes
C)  peroxisomes
D)  proteasomes
E)  spliceosome

Exam 8: Cytoplasmic Membrane Systems: Structure, function, and Membrane Trafficking

What is the general name for a molecule that physically links two different types of materials?

Correct Answer
verified

What are the functions of housekeeping receptors in the endocytic pathway? What is the function of signaling receptors in the endocytic pathway? How do the fates of housekeeping and signaling receptors generally differ?

Correct Answer
verified
Housekeeping receptors in the endocytic ...
View Answer

Which endosomes are typically located in the more interior part of the cell,near the nucleus?

Correct Answer
verified

What does the conformation-sensing enzyme UGGT do if it binds to a misfolded or incompletely folded glycoprotein?

Correct Answer
verified

The accumulation of misfolded proteins in the ER is a potentially lethal situation and thus causes the triggering of what process?

Correct Answer
verified

What is thought to direct the movement of vesicles through the cytoplasm to their final destination?

Correct Answer
verified

What allows the interface between the Sec13-Sec31 subunits to form cages of varying diameter,thus accommodating vesicles of varying size?

Correct Answer
verified

When Rabs have bound to GTP,what do they do?

Correct Answer
verified

Which part of the Golgi complex is thought to function primarily as a sorting station that distinguishes between proteins to be shipped back to the ER and those that are allowed to proceed to the next Golgi station?

Correct Answer
verified

What is the primary adaptor protein of the COPII coat that interacts specifically with the ER export signals in the cytosolic tails of membrane proteins that are destined to traffic on to the Golgi complex?

Correct Answer
verified

What is responsible for degrading misfolded proteins in the cytoplasm?

Correct Answer
verified

The two separate (basic) categories of uptake of extracellular materials into cytoplasmic vesicles are and .

Correct Answer
verified

How and where is the asymmetry of the phospholipid bilayers initially established?

Correct Answer
verified

What are the differences between early and late endosomes?

Correct Answer
verified

You wish to target a purified enzyme to the lysosomes of macrophages.How might you accomplish this?

Correct Answer
verified
If you treat the oligosaccharides of the...
View Answer

Cells are infected with a virus carrying a temperature-sensitive mutant VSVG gene that encodes a protein that cannot leave the ER of infected cells grown at restrictive temperatures.Thus,at higher temperatures,______________.

Correct Answer
verified

What enzyme transfers a block of sugars to asparagine residues of a polypeptide as it enters the RER?

Correct Answer
verified

Correct Answer
verified
Fowlase is a secretory protein...
View Answer

What removes the stroma-targeting domain and where does the removal occur?

Correct Answer
verified

Cells are infected with a vesicular stomatitis virus (VSV) strain in which a viral gene (VSVG) is fused to the green fluorescent protein gene.When the chimeric protein is synthesized,what pathway does it follow from synthesis until it leaves the cell?

Correct Answer
verified

Exam 8: Cytoplasmic Membrane Systems: Structure, function, and Membrane Trafficking

What is the general name for a molecule that physically links two different types of materials?

Correct AnswerverifiedShow Answer

What are the functions of housekeeping receptors in the endocytic pathway? What is the function of signaling receptors in the endocytic pathway? How do the fates of housekeeping and signaling receptors generally differ?

Correct AnswerverifiedHousekeeping receptors in the endocytic ...View AnswerShow Answer

Which endosomes are typically located in the more interior part of the cell,near the nucleus?

Correct AnswerverifiedShow Answer

What does the conformation-sensing enzyme UGGT do if it binds to a misfolded or incompletely folded glycoprotein?

Correct AnswerverifiedShow Answer

The accumulation of misfolded proteins in the ER is a potentially lethal situation and thus causes the triggering of what process?

Correct AnswerverifiedShow Answer

What is thought to direct the movement of vesicles through the cytoplasm to their final destination?

Correct AnswerverifiedShow Answer

What allows the interface between the Sec13-Sec31 subunits to form cages of varying diameter,thus accommodating vesicles of varying size?

Correct AnswerverifiedShow Answer

When Rabs have bound to GTP,what do they do?

Correct AnswerverifiedShow Answer

Which part of the Golgi complex is thought to function primarily as a sorting station that distinguishes between proteins to be shipped back to the ER and those that are allowed to proceed to the next Golgi station?

Correct AnswerverifiedShow Answer

What is the primary adaptor protein of the COPII coat that interacts specifically with the ER export signals in the cytosolic tails of membrane proteins that are destined to traffic on to the Golgi complex?

Correct AnswerverifiedShow Answer

What is responsible for degrading misfolded proteins in the cytoplasm?

Correct AnswerverifiedShow Answer

The two separate (basic) categories of uptake of extracellular materials into cytoplasmic vesicles are ______ and ______.

Correct AnswerverifiedShow Answer

How and where is the asymmetry of the phospholipid bilayers initially established?

Correct AnswerverifiedShow Answer

What are the differences between early and late endosomes?

Correct AnswerverifiedShow Answer

You wish to target a purified enzyme to the lysosomes of macrophages.How might you accomplish this?

Correct AnswerverifiedIf you treat the oligosaccharides of the...View AnswerShow Answer

Cells are infected with a virus carrying a temperature-sensitive mutant VSVG gene that encodes a protein that cannot leave the ER of infected cells grown at restrictive temperatures.Thus,at higher temperatures,______________.

Correct AnswerverifiedShow Answer

What enzyme transfers a block of sugars to asparagine residues of a polypeptide as it enters the RER?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedFowlase is a secretory protein...View AnswerShow Answer

What removes the stroma-targeting domain and where does the removal occur?

Correct AnswerverifiedShow Answer

Cells are infected with a vesicular stomatitis virus (VSV) strain in which a viral gene (VSVG) is fused to the green fluorescent protein gene.When the chimeric protein is synthesized,what pathway does it follow from synthesis until it leaves the cell?

Correct AnswerverifiedShow Answer

Correct Answer
verified

Correct Answer
verified
Housekeeping receptors in the endocytic ...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

The two separate (basic) categories of uptake of extracellular materials into cytoplasmic vesicles are and .

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
If you treat the oligosaccharides of the...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
Fowlase is a secretory protein...
View Answer

Correct Answer
verified

Correct Answer
verified