Question 1

Lysosomal proteins are marked by the addition of a phosphate to a _______ group.

Accepted Answer

A)  glucose 
B)  serine 
C)  GDP 
D)  mannose 
A)  glucose 
B)  serine 
C)  GDP 
D)  mannose

Question 2

Which statement describes evidence that supports the signal hypothesis as an explanation for how secretory proteins are targeted to the rough ER?

Accepted Answer

A)  The protein is larger when synthesized in vitro on free polysomes. 
B)  The secretory protein ends up in the cytosol when a short sequence is deleted by genetic engineering. 
C)  A normally cytosolic protein is secreted when a specific sequence is added to it by genetic engineering. 
D)  All of the above 
A)  The protein is larger when synthesized in vitro on free polysomes. 
B)  The secretory protein ends up in the cytosol when a short sequence is deleted by genetic engineering. 
C)  A normally cytosolic protein is secreted when a specific sequence is added to it by genetic engineering. 
D)  All of the above

Question 3

Adaptor proteins are involved in the selection of _______ to be incorporated into coated vesicles.

Accepted Answer

The answer of Adaptor proteins are involved in the selection...

Question 4

What deficiency causes I-cell disease?

Accepted Answer

A deficiency in the enzyme tha

Question 5

The unfolded protein response involves

Accepted Answer

A)  translation of most proteins. 
B)  increased synthesis of chaperones. 
C)  decreased proteasome activity. 
D)  All of the above 
A)  translation of most proteins. 
B)  increased synthesis of chaperones. 
C)  decreased proteasome activity. 
D)  All of the above

Question 6

How do hydrolytic enzymes get from the Golgi apparatus to lysosomes?

Accepted Answer

Hydrolytic enzymes accumulate on lysosom

Question 7

In proteins being made on rough ER, short spans of hydrophobic amino acids that form $\alpha$ helices

Accepted Answer

A)  induce a conformational change in the translocon, allowing them to exit into the ER membrane. 
B)  are posttranslationally inserted into the ER membrane by BiP. 
C)  are ubiquitinated and transferred into the cytosol for proteasomal degradation. 
D)  cause premature termination of translation, leading to the unfolded protein response. 
A)  induce a conformational change in the translocon, allowing them to exit into the ER membrane. 
B)  are posttranslationally inserted into the ER membrane by BiP. 
C)  are ubiquitinated and transferred into the cytosol for proteasomal degradation. 
D)  cause premature termination of translation, leading to the unfolded protein response.

Question 8

Clathrin coats are bound to specific receptors by a protein called

Accepted Answer

A)  an adaptor protein. 
B)  ARF. 
C)  COPI. 
D)  NSF. 
A)  an adaptor protein. 
B)  ARF. 
C)  COPI. 
D)  NSF.

Question 9

Suppose you are studying a mutant that you know is impaired in secretion, but you do not know the exact nature of the defect. You analyze the sugar content of some of the proteins purified from the mutant that you know should be N-glycosylated and find that fucose, galactose, and sialic acid residues are absent. Instead, only N-acetylglucosamine and mannose residues are evident. Where do you think the defect in secretion lies?

Accepted Answer

There is a defect in transport between t

Question 10

Most plasma membrane proteins in higher eukaryotic cells are synthesized on

Accepted Answer

A)  free ribosomes and inserted after translation into the plasma membrane. 
B)  rough ER ribosomes and carried to the plasma membrane by vesicles that pinch off from the Golgi apparatus. 
C)  rough ER ribosomes and carried to the plasma membrane by vesicles that pinch off from the rough ER. 
D)  ribosomes associated with the plasma membrane and inserted into the membrane cotranslationally. 
A)  free ribosomes and inserted after translation into the plasma membrane. 
B)  rough ER ribosomes and carried to the plasma membrane by vesicles that pinch off from the Golgi apparatus. 
C)  rough ER ribosomes and carried to the plasma membrane by vesicles that pinch off from the rough ER. 
D)  ribosomes associated with the plasma membrane and inserted into the membrane cotranslationally.

Question 11

Disulfide bonds within or between proteins form easily

Accepted Answer

A)  in the ER but not the cytosol. 
B)  in neither the cytosol nor the ER. 
C)  in the cytosol but not the ER. 
D)  in both the cytosol and the ER. 
A)  in the ER but not the cytosol. 
B)  in neither the cytosol nor the ER. 
C)  in the cytosol but not the ER. 
D)  in both the cytosol and the ER.

Question 12

In plant cells, vesicles transport proteins from the Golgi apparatus to

Accepted Answer

A)  lysosomes. 
B)  vacuoles. 
C)  chloroplasts. 
D)  mitochondria. 
A)  lysosomes. 
B)  vacuoles. 
C)  chloroplasts. 
D)  mitochondria.

Question 13

Describe the role of each of the following in targeting and processing proteins in the endoplasmic reticulum.
-A KDEL sequence

Accepted Answer

A KDEL sequence binds to the K

Question 14

The initial site of N-linked glycosylation is the Golgi apparatus.

Accepted Answer

A) True 
 B)False

Question 15

Imagine a transmembrane molecule that lies in the plasma membrane and acts as a receptor for an extracellular signaling molecule. When the ligand-binding domain is inserted into the ER during synthesis of this transmembrane molecule, will it lie on the lumen side of the ER or the cytoplasm side?

Accepted Answer

The ligand-binding domain will lie withi

Question 16

The sequence Lys-Asp-Glu-Leu (KDEL) serves as an ER retention signal for proteins by binding to KDEL receptors that

Accepted Answer

A)  hold the proteins in the rough ER. 
B)  hold the proteins in the smooth ER. 
C)  hold the proteins in both the smooth ER and rough ER and prevent their transport to the Golgi apparatus. 
D)  transport the proteins from the Golgi apparatus back to the ER. 
A)  hold the proteins in the rough ER. 
B)  hold the proteins in the smooth ER. 
C)  hold the proteins in both the smooth ER and rough ER and prevent their transport to the Golgi apparatus. 
D)  transport the proteins from the Golgi apparatus back to the ER.

Question 17

Defects in lysosomal enzyme levels can be corrected by _______ replacement therapy.

Accepted Answer

The answer of Defects in lysosomal enzyme levels can be...

Question 18

Vesicle formation is driven by the binding of clathrin or COP proteins.

Accepted Answer

A) True 
 B)False

Question 19

Polypeptides inside the ER are usually smaller than polypeptides synthesized from the same mRNA that have not entered the ER.

Accepted Answer

A) True 
 B)False

Question 20

In the "pulse-chase" experiment, Palade and colleagues studied the pathway taken by newly secreted proteins in pancreatic acinar cells by labeling them with radioactive amino acids, removing unused label, and determining their location within the cells at various time points. Which sequence represents the correct order in which the proteins were identified?

Accepted Answer

A)  Secretory vesicles $\rightarrow$Golgi apparatus $\rightarrow$ rough ER $\rightarrow$ nucleus 
B)  Golgi apparatus $\rightarrow$ rough ER $\rightarrow$ nucleus $\rightarrow$secretory vesicles 
C)  Rough ER $\rightarrow$ secretory vesicles $\rightarrow$ Golgi apparatus 
D)  Rough ER $\rightarrow$Golgi apparatus $\rightarrow$ secretory vesicles 
A)  Secretory vesicles $\rightarrow$Golgi apparatus $\rightarrow$ rough ER $\rightarrow$ nucleus 
B)  Golgi apparatus $\rightarrow$ rough ER $\rightarrow$ nucleus $\rightarrow$secretory vesicles 
C)  Rough ER $\rightarrow$ secretory vesicles $\rightarrow$ Golgi apparatus 
D)  Rough ER $\rightarrow$Golgi apparatus $\rightarrow$ secretory vesicles

Lysosomal proteins are marked by the addition of a phosphate to a _______ group.

Which statement describes evidence that supports the signal hypothesis as an explanation for how secretory proteins are targeted to the rough ER?

Adaptor proteins are involved in the selection of _______ to be incorporated into coated vesicles.

What deficiency causes I-cell disease?

The unfolded protein response involves

How do hydrolytic enzymes get from the Golgi apparatus to lysosomes?

In proteins being made on rough ER, short spans of hydrophobic amino acids that form $\alpha$ helices

Clathrin coats are bound to specific receptors by a protein called

Most plasma membrane proteins in higher eukaryotic cells are synthesized on

Disulfide bonds within or between proteins form easily

In plant cells, vesicles transport proteins from the Golgi apparatus to

Describe the role of each of the following in targeting and processing proteins in the endoplasmic reticulum. -A KDEL sequence

The initial site of N-linked glycosylation is the Golgi apparatus.

Imagine a transmembrane molecule that lies in the plasma membrane and acts as a receptor for an extracellular signaling molecule. When the ligand-binding domain is inserted into the ER during synthesis of this transmembrane molecule, will it lie on the lumen side of the ER or the cytoplasm side?

The sequence Lys-Asp-Glu-Leu (KDEL) serves as an ER retention signal for proteins by binding to KDEL receptors that

Defects in lysosomal enzyme levels can be corrected by _______ replacement therapy.

Vesicle formation is driven by the binding of clathrin or COP proteins.

Polypeptides inside the ER are usually smaller than polypeptides synthesized from the same mRNA that have not entered the ER.

An Overview of Cells and Cell Research

Molecules and Membranes

Bioenergetics and Metabolism

Fundamentals of Molecular Biology

Genomics, Proteomics, and Systems Biology

Genes and Genomes

Replication, Maintenance, and Rearrangements of Genomic Dna

RNA Synthesis and Processing

Transcriptional Regulation and Epigenetics

Protein Synthesis, Processing, and Regulation

The Nucleus

Mitochondria, Chloroplasts, and Peroxisomes

The Cytoskeleton and Cell Movement

The Plasma Membrane

Cell Walls, the Extracellular Matrix, and Cell Interactions

Cell Signaling

The Cell Cycle

Cell Death and Cell Renewal

Cancer

Filters

Exam 12: Protein Sorting and Transport

Lysosomal proteins are marked by the addition of a phosphate to a _______ group.

Which statement describes evidence that supports the signal hypothesis as an explanation for how secretory proteins are targeted to the rough ER?

Adaptor proteins are involved in the selection of _______ to be incorporated into coated vesicles.

What deficiency causes I-cell disease?

The unfolded protein response involves

How do hydrolytic enzymes get from the Golgi apparatus to lysosomes?

In proteins being made on rough ER, short spans of hydrophobic amino acids that form α\alphaα helices

Clathrin coats are bound to specific receptors by a protein called

Most plasma membrane proteins in higher eukaryotic cells are synthesized on

Disulfide bonds within or between proteins form easily

In plant cells, vesicles transport proteins from the Golgi apparatus to

Describe the role of each of the following in targeting and processing proteins in the endoplasmic reticulum. -A KDEL sequence

The initial site of N-linked glycosylation is the Golgi apparatus.

Imagine a transmembrane molecule that lies in the plasma membrane and acts as a receptor for an extracellular signaling molecule. When the ligand-binding domain is inserted into the ER during synthesis of this transmembrane molecule, will it lie on the lumen side of the ER or the cytoplasm side?

The sequence Lys-Asp-Glu-Leu (KDEL) serves as an ER retention signal for proteins by binding to KDEL receptors that

Defects in lysosomal enzyme levels can be corrected by _______ replacement therapy.

Vesicle formation is driven by the binding of clathrin or COP proteins.

Polypeptides inside the ER are usually smaller than polypeptides synthesized from the same mRNA that have not entered the ER.

An Overview of Cells and Cell Research

Molecules and Membranes

Bioenergetics and Metabolism

Fundamentals of Molecular Biology

Genomics, Proteomics, and Systems Biology

Genes and Genomes

Replication, Maintenance, and Rearrangements of Genomic Dna

RNA Synthesis and Processing

Transcriptional Regulation and Epigenetics

Protein Synthesis, Processing, and Regulation

The Nucleus

Mitochondria, Chloroplasts, and Peroxisomes

The Cytoskeleton and Cell Movement

The Plasma Membrane

Cell Walls, the Extracellular Matrix, and Cell Interactions

Cell Signaling

The Cell Cycle

Cell Death and Cell Renewal

Cancer

Filters

In proteins being made on rough ER, short spans of hydrophobic amino acids that form $\alpha$ helices