Question 1

What GTP-binding protein is associated with the formation of the COPI coat on COPI-coated vesicles?

Accepted Answer

A) Sar1 
B) Arf Arf 
C) ARF1 (adenosylation ribose factor) 
D) Ras 
E) Src 
A) Sar1 
B) Arf Arf 
C) ARF1 (adenosylation ribose factor) 
D) Ras 
E) Src

Question 2

A cellular phenomenon called RNA interference is a process in which cells produce small RNAs called _______ that bind to specific mRNAs and inhibit the translation of these mRNAs into proteins.

Accepted Answer

A) snRNAs 
B) isRNAs 
C) mRNAs 
D) RNAsi 
E) siRNAs 
A) snRNAs 
B) isRNAs 
C) mRNAs 
D) RNAsi 
E) siRNAs

Question 3

What appears to be the purpose of molecular chaperones like BiP?

Accepted Answer

A) They recognize and bind to unfolded or misfolded proteins and help them attain their native structure. 
B) They recognize and bind to unfolded or misfolded DNAs and help them attain their native structure. 
C) They recognize and bind to unfolded or misfolded RNAs and help them attain their native structure. 
D) They recognize and bind unfolded or misfolded carbohydrates and help them lose their native shape. 
E) They transport secretory proteins into secretory vesicles. 
A) They recognize and bind to unfolded or misfolded proteins and help them attain their native structure. 
B) They recognize and bind to unfolded or misfolded DNAs and help them attain their native structure. 
C) They recognize and bind to unfolded or misfolded RNAs and help them attain their native structure. 
D) They recognize and bind unfolded or misfolded carbohydrates and help them lose their native shape. 
E) They transport secretory proteins into secretory vesicles.

Question 4

Proteins destined for the inner mitochondrial membrane or the mitochondrial matrix must pass through the _________.

Accepted Answer

A) TOM complex 
B) TIM complex 
C) at least one protein-lined channel 
D) intermembrane space 
E) All of these are correct. 
A) TOM complex 
B) TIM complex 
C) at least one protein-lined channel 
D) intermembrane space 
E) All of these are correct.

Question 5

Substances that enter the cell by receptor-mediated endocytosis bind receptors that collect in specialized domains of the plasma membrane called ______.

Accepted Answer

A) coated vesicles 
B) coated pits 
C) RME pits 
D) gap junctions 
E) tight junctions 
A) coated vesicles 
B) coated pits 
C) RME pits 
D) gap junctions 
E) tight junctions

Question 6

How are integral membrane proteins thought to enter the lipid bilayer?

Accepted Answer

A) They insert into the membrane from the RER lumen after their synthesis is complete. 
B) The aqueous translocon channel seems to have a gate that continuously opens and closes,giving each nascent polypeptide segment a chance to partition itself into the lipid bilayer's hydrophobic core. 
C) They insert into the membrane from the cytosol after their synthesis is complete. 
D) It is thought that they burrow into the lipid bilayer. 
E) It is thought that they are enzymatically implanted in the lipid bilayer. 
A) They insert into the membrane from the RER lumen after their synthesis is complete. 
B) The aqueous translocon channel seems to have a gate that continuously opens and closes,giving each nascent polypeptide segment a chance to partition itself into the lipid bilayer's hydrophobic core. 
C) They insert into the membrane from the cytosol after their synthesis is complete. 
D) It is thought that they burrow into the lipid bilayer. 
E) It is thought that they are enzymatically implanted in the lipid bilayer.

Question 7

The best-studied adaptors that participate in the formation of the coated pits and coated vesicles of clathrin-mediated endocytosis are the _____ adaptors.

Accepted Answer

A) COPII 
B) GGA 
C) AP2 
D) clathrin 
E) COPI 
A) COPII 
B) GGA 
C) AP2 
D) clathrin 
E) COPI

Question 8

Which of the following organelles imports proteins through one or more outer boundary membranes?

Accepted Answer

A) the nucleus 
B) mitochondria 
C) chloroplasts 
D) peroxisomes 
E) All of these are correct. 
A) the nucleus 
B) mitochondria 
C) chloroplasts 
D) peroxisomes 
E) All of these are correct.

Question 9

When electron micrographs were first taken of the cell interior,what kinds of membranous structures were seen?

Accepted Answer

A) membrane-bound vesicles of varying diameter,containing material of different electron density 
B) long channels bounded by membranes and radiating through the cytoplasm 
C) an interconnected network of canals 
D) stacks of flattened,membrane-bound sacs called cisternae 
E) All of these are correct. 
A) membrane-bound vesicles of varying diameter,containing material of different electron density 
B) long channels bounded by membranes and radiating through the cytoplasm 
C) an interconnected network of canals 
D) stacks of flattened,membrane-bound sacs called cisternae 
E) All of these are correct.

Question 10

What components below are selected for transport by vesicles originating in the Golgi complex?

Accepted Answer

A) secretory proteins 
B) lysosomal proteins 
C) proteins required to dock the vesicle to an acceptor membrane 
D) proteins required to target the vesicle to an acceptor membrane 
E) All of these components. 
A) secretory proteins 
B) lysosomal proteins 
C) proteins required to dock the vesicle to an acceptor membrane 
D) proteins required to target the vesicle to an acceptor membrane 
E) All of these components.

Question 11

Which phosphoinositide is localized at the TGN,secretory granules and synaptic vesicles?

Accepted Answer

A) PI(4,5)P2 
B) PI(4)P 
C) PI(3,5)P2 
D) PI(3)P 
E) PI(5)P 
A) PI(4,5)P2 
B) PI(4)P 
C) PI(3,5)P2 
D) PI(3)P 
E) PI(5)P

Question 12

TB 8.008 Elevated temperatures at which temperature-sensitive mutants do not work are called ________ temperatures.

Accepted Answer

A) restrictive 
B) permissive 
C) temperature-sensitive 
D) frame-shift 
E) point 
A) restrictive 
B) permissive 
C) temperature-sensitive 
D) frame-shift 
E) point

Question 13

When a mitochondrial chaperone helps a mitochondrial matrix protein into the matrix by biased diffusion,the chaperone is said to be acting as a(n)______.

Accepted Answer

A) Brownian motion 
B) biased diffuser 
C) Brownian ratchet 
D) misratchet 
E) unbiased diffuser 
A) Brownian motion 
B) biased diffuser 
C) Brownian ratchet 
D) misratchet 
E) unbiased diffuser

Question 14

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 
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 15

What kind(s)of modifications are made in proteins as they move through the Golgi complex?

Accepted Answer

A) The protein's carbohydrates are modified by a series of stepwise enzymatic reactions. 
B) Amino acids can be added to either end of the polypeptide chain. 
C) Amino acids in the proteins may be chemically altered into nucleic acids. 
D) Small segments of amino acids can be added into the center of an existing protein. 
E) All of these are correct. 
A) The protein's carbohydrates are modified by a series of stepwise enzymatic reactions. 
B) Amino acids can be added to either end of the polypeptide chain. 
C) Amino acids in the proteins may be chemically altered into nucleic acids. 
D) Small segments of amino acids can be added into the center of an existing protein. 
E) All of these are correct.

Question 16

What effect does the binding of the SRP to the growing polypeptide chain and the ribosome have on protein synthesis?

Accepted Answer

A) Protein synthesis accelerates. 
B) Protein synthesis ceases temporarily. 
C) Protein synthesis ceases permanently. 
D) Protein synthesis is terminated. 
E) The ribosome dissociates. 
A) Protein synthesis accelerates. 
B) Protein synthesis ceases temporarily. 
C) Protein synthesis ceases permanently. 
D) Protein synthesis is terminated. 
E) The ribosome dissociates.

Question 17

What happens to yeast cells that cannot transport proteins into the ER lumen cotranslationally?

Accepted Answer

A) The die. 
B) They hibernate. 
C) They survive,but grow more slowly than normal yeast cells. 
D) They divide more frequently. 
E) Their lifespans are lengthened. 
A) The die. 
B) They hibernate. 
C) They survive,but grow more slowly than normal yeast cells. 
D) They divide more frequently. 
E) Their lifespans are lengthened.

Question 18

Sec23 and Sec24 bind together to form a "banana-shaped" dimer.What is the purpose of this dimer

Accepted Answer

A) Because of its linear shape,it firms up the membrane. 
B) Because of its curved shape,the dimer puts pressure on the membrane surface to help it further bend into a curved bud. 
C) Because of its curved shape,the dimer puts pressure on the membrane surface to help it disintegrate. 
D) The dimer stabilizes the Golgi complex membrane. 
E) The dimer joins with other dimers to form a remarkably stable cage. 
A) Because of its linear shape,it firms up the membrane. 
B) Because of its curved shape,the dimer puts pressure on the membrane surface to help it further bend into a curved bud. 
C) Because of its curved shape,the dimer puts pressure on the membrane surface to help it disintegrate. 
D) The dimer stabilizes the Golgi complex membrane. 
E) The dimer joins with other dimers to form a remarkably stable cage.

Question 19

If you treated a macrophage with colchicine (a microtubular inhibitor),what would be likely to happen to the rate of phagocytosis? What would be likely to happen to the rate of phagocytosis if you treated the macrophage with an inhibitor of microfilament contractile activities?

Accepted Answer

A) Nothing would happen after colchicine exposure.The rate would rise after cytochalasin B exposure 
B) The rate would drop after colchicine exposure.Nothing would happen after cytochalasin B exposure. 
C) Nothing would happen after colchicine exposure.The rate would drop after cytochalasin B exposure. 
D) The rate would rise after colchicine exposure.Nothing would happen after cytochalasin B exposure. 
E) Nothing would happen after treatment with either inhibitor. 
A) Nothing would happen after colchicine exposure.The rate would rise after cytochalasin B exposure 
B) The rate would drop after colchicine exposure.Nothing would happen after cytochalasin B exposure. 
C) Nothing would happen after colchicine exposure.The rate would drop after cytochalasin B exposure. 
D) The rate would rise after colchicine exposure.Nothing would happen after cytochalasin B exposure. 
E) Nothing would happen after treatment with either inhibitor.

Question 20

A scientist is studying the movement of vesicles between different cellular compartments.She starts by treating the cells with a number of known inhibitors of cellular activities.One of them greatly increases the number of fuzzy-coated vesicles.What is a possible explanation? The effect of the inhibitor can be reversed if intracellular GTP is added in large amounts.What might explain this?

Accepted Answer

The inhibitor could inhibit some action

What GTP-binding protein is associated with the formation of the COPI coat on COPI-coated vesicles?

A cellular phenomenon called RNA interference is a process in which cells produce small RNAs called _______ that bind to specific mRNAs and inhibit the translation of these mRNAs into proteins.

What appears to be the purpose of molecular chaperones like BiP?

Proteins destined for the inner mitochondrial membrane or the mitochondrial matrix must pass through the _________.

Substances that enter the cell by receptor-mediated endocytosis bind receptors that collect in specialized domains of the plasma membrane called ______.

How are integral membrane proteins thought to enter the lipid bilayer?

The best-studied adaptors that participate in the formation of the coated pits and coated vesicles of clathrin-mediated endocytosis are the _____ adaptors.

Which of the following organelles imports proteins through one or more outer boundary membranes?

When electron micrographs were first taken of the cell interior,what kinds of membranous structures were seen?

What components below are selected for transport by vesicles originating in the Golgi complex?

Which phosphoinositide is localized at the TGN,secretory granules and synaptic vesicles?

TB 8.008 Elevated temperatures at which temperature-sensitive mutants do not work are called ________ temperatures.

When a mitochondrial chaperone helps a mitochondrial matrix protein into the matrix by biased diffusion,the chaperone is said to be acting as a(n)______.

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

What kind(s)of modifications are made in proteins as they move through the Golgi complex?

What effect does the binding of the SRP to the growing polypeptide chain and the ribosome have on protein synthesis?

What happens to yeast cells that cannot transport proteins into the ER lumen cotranslationally?

Sec23 and Sec24 bind together to form a "banana-shaped" dimer.What is the purpose of this dimer

If you treated a macrophage with colchicine (a microtubular inhibitor),what would be likely to happen to the rate of phagocytosis? What would be likely to happen to the rate of phagocytosis if you treated the macrophage with an inhibitor of microfilament contractile activities?

Introduction to the Study of Cell and Molecular Biology

The Chemical Basis of Life

Bioenergetics, Enzymes, and Metabolism

The Structure and Function of the Plasma Membrane

Aerobic Respiration and the Mitochondrion

Photosynthesis and the Chloroplast

Interactions Between Cells and Their Environment

The Cytoskeleton and Cell Motility

The Nature of the Gene and the Genome

Gene Expression: From Transcription to Translation

Control of Gene Expression

Dna Replication and Repair

Cellular Reproduction

Cell Signaling and Signal Transduction: Communication Between Cells

Cancer

The Immune Response

Techniques in Cell and Molecular Biology

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

What GTP-binding protein is associated with the formation of the COPI coat on COPI-coated vesicles?

A cellular phenomenon called RNA interference is a process in which cells produce small RNAs called _______ that bind to specific mRNAs and inhibit the translation of these mRNAs into proteins.

What appears to be the purpose of molecular chaperones like BiP?

Proteins destined for the inner mitochondrial membrane or the mitochondrial matrix must pass through the _________.

Substances that enter the cell by receptor-mediated endocytosis bind receptors that collect in specialized domains of the plasma membrane called ______.

How are integral membrane proteins thought to enter the lipid bilayer?

The best-studied adaptors that participate in the formation of the coated pits and coated vesicles of clathrin-mediated endocytosis are the _____ adaptors.

Which of the following organelles imports proteins through one or more outer boundary membranes?

When electron micrographs were first taken of the cell interior,what kinds of membranous structures were seen?

What components below are selected for transport by vesicles originating in the Golgi complex?

Which phosphoinositide is localized at the TGN,secretory granules and synaptic vesicles?

TB 8.008 Elevated temperatures at which temperature-sensitive mutants do not work are called ________ temperatures.

When a mitochondrial chaperone helps a mitochondrial matrix protein into the matrix by biased diffusion,the chaperone is said to be acting as a(n)______.

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

What kind(s)of modifications are made in proteins as they move through the Golgi complex?

What effect does the binding of the SRP to the growing polypeptide chain and the ribosome have on protein synthesis?

What happens to yeast cells that cannot transport proteins into the ER lumen cotranslationally?

Sec23 and Sec24 bind together to form a "banana-shaped" dimer.What is the purpose of this dimer

If you treated a macrophage with colchicine (a microtubular inhibitor),what would be likely to happen to the rate of phagocytosis? What would be likely to happen to the rate of phagocytosis if you treated the macrophage with an inhibitor of microfilament contractile activities?

Introduction to the Study of Cell and Molecular Biology

The Chemical Basis of Life

Bioenergetics, Enzymes, and Metabolism

The Structure and Function of the Plasma Membrane

Aerobic Respiration and the Mitochondrion

Photosynthesis and the Chloroplast

Interactions Between Cells and Their Environment

The Cytoskeleton and Cell Motility

The Nature of the Gene and the Genome

Gene Expression: From Transcription to Translation

Control of Gene Expression

Dna Replication and Repair

Cellular Reproduction

Cell Signaling and Signal Transduction: Communication Between Cells

Cancer

The Immune Response

Techniques in Cell and Molecular Biology

Filters