Question 1

Endoglycosidase D is a useful reagent because it allows scientists to distinguish glycosylated proteins that:

Accepted Answer

A) remain in the cis-Golgi. 
B) remain in the trans-Golgi. 
C) remain in the ER. 
D) get secreted. 
A) remain in the cis-Golgi. 
B) remain in the trans-Golgi. 
C) remain in the ER. 
D) get secreted. C

Question 2

How are different coat proteins recruited to different sites within the cell?

Accepted Answer

There are three known classes of coat proteins: clathrin,COPI,and COPII.Small GTPases recruit each to membranes.Sar1 recruits COPII.Sar1 itself is activated by a guanine nucleotide exchange factor,Sec12,an ER integral membrane protein.ARF recruits both clathrin and COPII.How ARF,or different isoforms of ARF,and guanine nucleotide exchange factor(s)recruit different coat protein/adapters to different sites is not yet known.

Question 3

Acidification of endosomes is important in dissociating:

Accepted Answer

A) cholesterol from LDL. 
B) iron from transferrin. 
C) transferrin from the transferrin receptor. 
D) all of the above 
A) cholesterol from LDL. 
B) iron from transferrin. 
C) transferrin from the transferrin receptor. 
D) all of the above B

Question 4

How can the direction in which vesicles move in a VSV G-based,cell-free system for transport between Golgi compartments be distinguished?

Accepted Answer

Certainly,the results from such a cell-f

Question 5

The LDL receptor is a receptor for:

Accepted Answer

A) apolipoprotein B. 
B) receptor-mediated endocytosis of LDL. 
C) cell signaling via activation of adenylate cyclase. 
D) apolipoprotein B and receptor-mediated endocytosis of LDL. 
A) apolipoprotein B. 
B) receptor-mediated endocytosis of LDL. 
C) cell signaling via activation of adenylate cyclase. 
D) apolipoprotein B and receptor-mediated endocytosis of LDL.

Question 6

What is the role of vesicles in the early stages of the secretory pathway such as ER to Golgi trafficking?

Accepted Answer

There are two classes of coat proteins i

Question 7

Vesicle budding recruits proteins that are needed for subsequent:

Accepted Answer

A) invagination of the vesicle into the ER lumen. 
B) selective vesicle targeting and fusion. 
C) shedding of integral membrane proteins into the cytosol. 
D) assembly of chromosome folding machinery. 
A) invagination of the vesicle into the ER lumen. 
B) selective vesicle targeting and fusion. 
C) shedding of integral membrane proteins into the cytosol. 
D) assembly of chromosome folding machinery.

Question 8

Given the wild type (normal)yeast on the left and the mutant yeast on the right,identify the defective phenotype for the mutant.

Accepted Answer

A) entry into the ER 
B) fusion of transport vesicles from the ER to the Golgi 
C) budding from the Golgi to secretory vesicles 
D) fusion of secretory vesicles with the plasma membrane 
A) entry into the ER 
B) fusion of transport vesicles from the ER to the Golgi 
C) budding from the Golgi to secretory vesicles 
D) fusion of secretory vesicles with the plasma membrane

Question 9

Which of the following small GTPases are NOT involved in vesicle budding or docking?

Accepted Answer

A) ARF 
B) rab1 
C) ras 
D) Sar1p 
A) ARF 
B) rab1 
C) ras 
D) Sar1p

Question 10

The mannose 6-phosphate residue is important,as it is required to target soluble enzymes to the lysosome.The two enzymes responsible for attaching this residue onto these soluble enzymes reside in the:

Accepted Answer

A) RER. 
B) cis-Golgi. 
C) medial-Golgi. 
D) trans-Golgi. 
A) RER. 
B) cis-Golgi. 
C) medial-Golgi. 
D) trans-Golgi.

Question 11

The discovery of green fluorescent protein (GFP)has greatly facilitated living cell experiments because:

Accepted Answer

A) GFP is green. 
B) GFP requires a jellyfish-specific cofactor. 
C) GFP sequences may be readily fused to those of other proteins. 
D) wild-type GFP folding is adapted to normal seawater temperatures,15-25 °C. 
A) GFP is green. 
B) GFP requires a jellyfish-specific cofactor. 
C) GFP sequences may be readily fused to those of other proteins. 
D) wild-type GFP folding is adapted to normal seawater temperatures,15-25 °C.

Question 12

How are clathrin-coated vesicles pinched off?

Accepted Answer

Clathrin-coated vesicles are pinched off

Question 13

The presence of clathrin mediates vesicular transport:

Accepted Answer

A) from ER to cis-Golgi. 
B) trans-Golgi to endosome. 
C) nuclear membrane to endosome. 
D) plasma membrane to trans-Golgi. 
A) from ER to cis-Golgi. 
B) trans-Golgi to endosome. 
C) nuclear membrane to endosome. 
D) plasma membrane to trans-Golgi.

Question 14

Which of the following is TRUE about lysosomes?

Accepted Answer

A) They contain enzymes only capable of breaking down nucleic acids. 
B) They are bound by a single membrane but can engulf organelles containing double membranes. 
C) Proteins targeted to the lysosome are glycosylated in the ER and a specific mannose is phosphorylated. 
D) The final,functional state of lysosomal enzymes contains mannose-6-phosphate. 
A) They contain enzymes only capable of breaking down nucleic acids. 
B) They are bound by a single membrane but can engulf organelles containing double membranes. 
C) Proteins targeted to the lysosome are glycosylated in the ER and a specific mannose is phosphorylated. 
D) The final,functional state of lysosomal enzymes contains mannose-6-phosphate.

Question 15

COPI coat proteins mediate transport between the Golgi apparatus and other organelles.

Accepted Answer

A) anterograde 
B) enterograde 
C) retrograde 
D) siderograde 
A) anterograde 
B) enterograde 
C) retrograde 
D) siderograde

Question 16

What is autophagy?

Accepted Answer

Autophagy ("eating oneself")is the deliv

Question 17

Soluble and membrane proteins advance through the Golgi complex by:

Accepted Answer

A) cisternal progression. 
B) stable continuities between Golgi cisterna. 
C) transient continuities between Golgi cisterna. 
D) vesicular transport. 
A) cisternal progression. 
B) stable continuities between Golgi cisterna. 
C) transient continuities between Golgi cisterna. 
D) vesicular transport.

Question 18

An important molecule for generating fatty acids in the cell enters via receptor-mediated endocytosis.The complex formed between the receptor on the plasma membrane and the important molecule is stable only at neutral pH.Based on this knowledge,you would predict:

Accepted Answer

A) a COPII-coated vesicle will be required for import. 
B) the important molecule enters the cell via a protein channel. 
C) both the molecule and the receptor are degraded to release the molecule from the receptor. 
D) the molecule is released from the receptor in the endosome. 
A) a COPII-coated vesicle will be required for import. 
B) the important molecule enters the cell via a protein channel. 
C) both the molecule and the receptor are degraded to release the molecule from the receptor. 
D) the molecule is released from the receptor in the endosome.

Question 19

In hepatocytes,the process by which apically destined proteins travel from the basolateral region across the cell before fusing with the apical membrane is called:

Accepted Answer

A) exocytosis. 
B) transcytosis. 
C) endocytosis. 
D) none of the above 
A) exocytosis. 
B) transcytosis. 
C) endocytosis. 
D) none of the above

Question 20

Cell-free transport assays:

Accepted Answer

A) complement genetic approaches to the secretory pathway. 
B) often probe for changes in the glycosylation state of transported proteins. 
C) provide a means to test the effect of added purified proteins. 
D) all of the above 
A) complement genetic approaches to the secretory pathway. 
B) often probe for changes in the glycosylation state of transported proteins. 
C) provide a means to test the effect of added purified proteins. 
D) all of the above

Exam 13: Vesicular Traffic, Secretion, and Endocytosis

Endoglycosidase D is a useful reagent because it allows scientists to distinguish glycosylated proteins that:

How are different coat proteins recruited to different sites within the cell?

Acidification of endosomes is important in dissociating:

How can the direction in which vesicles move in a VSV G-based,cell-free system for transport between Golgi compartments be distinguished?

The LDL receptor is a receptor for:

What is the role of vesicles in the early stages of the secretory pathway such as ER to Golgi trafficking?

Vesicle budding recruits proteins that are needed for subsequent:

Given the wild type (normal)yeast on the left and the mutant yeast on the right,identify the defective phenotype for the mutant.

Which of the following small GTPases are NOT involved in vesicle budding or docking?

The mannose 6-phosphate residue is important,as it is required to target soluble enzymes to the lysosome.The two enzymes responsible for attaching this residue onto these soluble enzymes reside in the:

The discovery of green fluorescent protein (GFP)has greatly facilitated living cell experiments because:

How are clathrin-coated vesicles pinched off?

The presence of clathrin mediates vesicular transport:

Which of the following is TRUE about lysosomes?

COPI coat proteins mediate transport between the Golgi apparatus and other organelles.

What is autophagy?

Soluble and membrane proteins advance through the Golgi complex by:

An important molecule for generating fatty acids in the cell enters via receptor-mediated endocytosis.The complex formed between the receptor on the plasma membrane and the important molecule is stable only at neutral pH.Based on this knowledge,you would predict:

In hepatocytes,the process by which apically destined proteins travel from the basolateral region across the cell before fusing with the apical membrane is called:

Cell-free transport assays:

Chemical Foundations

Molecular Genetic Techniques

Protein Structure and Function

Culturing and Visualizing Cells

Fundamental Molecular Genetic Mechanisms

Bio-membrane Structure

Genes Genomics and Chromosomes

Transcriptional Control of Gene Expression

Post-Transcriptional Gene Control

Transmembrane Transport of Ions and Small Molecules

Cellular Energetics

Moving Proteins Into Membranes and Organelles

Signal Transduction and G-Protein Coupled Receptors

Signaling Pathways That Control Gene Activity

Cell Organization and Movement I: Microfilaments

Cell Organization and Movement II: Microtubules and Intermediate Filaments

Regulating the Eukaryotic Cell Cycle

Integrating Cells Into Tissues

Cell Birth, Lineage, and Death

Nerve Cells

Immunology

Cancer

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