Question 1

How does the lac repressor inhibit transcription?

Accepted Answer

A)  It binds to the RNA polymerase and prevents its association to the DNA. 
B)  It binds to the DNA and prevents the RNA polymerase from unwinding and transcribing the DNA. 
C)  It binds to RNA polymerase and causes a frame shift, thus producing an mRNA with a nonsense mutation. 
D)  It binds to the mRNA molecule, preventing ribosomes from binding. 
E)  None of the answers is correct. 
A)  It binds to the RNA polymerase and prevents its association to the DNA. 
B)  It binds to the DNA and prevents the RNA polymerase from unwinding and transcribing the DNA. 
C)  It binds to RNA polymerase and causes a frame shift, thus producing an mRNA with a nonsense mutation. 
D)  It binds to the mRNA molecule, preventing ribosomes from binding. 
E)  None of the answers is correct.

Question 2

Why do many DNA-binding proteins bind as a dimer?

Accepted Answer

The 2-fold axis of s

Question 3

What is a complex community of prokaryotes?

Accepted Answer

A)  quorum 
B)  colony 
C)  satellite 
D)  leader colony 
E)  biofilm 
A)  quorum 
B)  colony 
C)  satellite 
D)  leader colony 
E)  biofilm

Question 4

The λ repressor protein blocks transcription of ____________________encoded by the virus.

Accepted Answer

The answer of The λ repressor protein blocks transcription of...

Question 5

Many DNA binding proteins,including the CAP and lac repressor,contain a(n)________ in their structure.

Accepted Answer

A)  pair of β strands 
B)  helix-turn-helix motif 
C)  zinc finger motif 
D)  extensive β-barrel 
E)  None of the answers is correct. 
A)  pair of β strands 
B)  helix-turn-helix motif 
C)  zinc finger motif 
D)  extensive β-barrel 
E)  None of the answers is correct.

Question 6

What substrate forms a colored product in the presence of $\beta$-galactosidase?

Accepted Answer

A)  p-nitrophenyl galactose 
B)  Coomassie-galactose 
C)  ethidium-galactose 
D)  X-gal 
E)  None of the answers is correct. 
A)  p-nitrophenyl galactose 
B)  Coomassie-galactose 
C)  ethidium-galactose 
D)  X-gal 
E)  None of the answers is correct.

Question 7

What kind of expression governs genes that are expressed at all times?

Accepted Answer

A)  constitutive 
B)  conservative 
C)  conscripted 
D)  consecutive 
E)  constituent 
A)  constitutive 
B)  conservative 
C)  conscripted 
D)  consecutive 
E)  constituent

Question 8

What is the relationship between gene regulation and sequences in the genome?

Accepted Answer

It is important to remember that the gen

Question 9

What is the binding unit for the methionine repressor?

Accepted Answer

A)  a pair of β strands 
B)  helix-turn-helix motif 
C)  zinc finger motif 
D)  a region with no discernable secondary structure 
E)  a pair of β strands and zinc finger motif 
A)  a pair of β strands 
B)  helix-turn-helix motif 
C)  zinc finger motif 
D)  a region with no discernable secondary structure 
E)  a pair of β strands and zinc finger motif

Question 10

Chemicals released from cells in response to population density and that inhibit gene expression are called

Accepted Answer

A)  autoattenuators. 
B)  autorepressors. 
C)  autoinducers. 
D)  catabolite repressors. 
E)  None of the answers is correct. 
A)  autoattenuators. 
B)  autorepressors. 
C)  autoinducers. 
D)  catabolite repressors. 
E)  None of the answers is correct.

Question 11

What is the first step in gene expression control?

Accepted Answer

A)  control of translation 
B)  control of mRNA processing 
C)  control of transcription 
D)  control of replication 
E)  None of the answers is correct. 
A)  control of translation 
B)  control of mRNA processing 
C)  control of transcription 
D)  control of replication 
E)  None of the answers is correct.

Question 12

What name describes the inhibitory effect of glucose,caused by its effect on cAMP levels?

Accepted Answer

A)  glucose repression 
B)  lactose repression 
C)  cAMP repression 
D)  anabolite repression 
E)  catabolite repression 
A)  glucose repression 
B)  lactose repression 
C)  cAMP repression 
D)  anabolite repression 
E)  catabolite repression

Question 13

What reaction is carried out by β-galactosidase?

Accepted Answer

A)  Lactose is hydrolyzed to galactose and sucrose. 
B)  Lactose is hydrolyzed to galactose and glucose. 
C)  Lactose is hydrolyzed to two molecules of glucose. 
D)  Lactose is hydrolyzed to two molecules of galactose. 
E)  None of the answers is correct. 
A)  Lactose is hydrolyzed to galactose and sucrose. 
B)  Lactose is hydrolyzed to galactose and glucose. 
C)  Lactose is hydrolyzed to two molecules of glucose. 
D)  Lactose is hydrolyzed to two molecules of galactose. 
E)  None of the answers is correct.

Question 14

What are biofilms,and why are they medically important?

Accepted Answer

Biofilms are specialized structures form

Question 15

How does the Cro protein promote the lytic state?

Accepted Answer

Cro and λ repressor both bind to three b

Question 16

Which of the following is the inducer of the lac operon in cells?

Accepted Answer

A)  lactose 
B)  galactose 
C)  allolactose 
D)  glucose 
E)  isopropylthiogalactopyranoside 
A)  lactose 
B)  galactose 
C)  allolactose 
D)  glucose 
E)  isopropylthiogalactopyranoside

Question 17

Which of the following is produced when tryptophan levels are low?

Accepted Answer

A)  162-nucleotide trp mRNA leader sequence 
B)  7000-nucleotide trp mRNA 
C)  130-nucleotide trp mRNA 
D)  162-nucleotide trp mRNA leader sequence and 7000-nucleotide trp mRNA 
E)  7000-nucleotide trp mRNA and 130-nucleotide trp mRNA 
A)  162-nucleotide trp mRNA leader sequence 
B)  7000-nucleotide trp mRNA 
C)  130-nucleotide trp mRNA 
D)  162-nucleotide trp mRNA leader sequence and 7000-nucleotide trp mRNA 
E)  7000-nucleotide trp mRNA and 130-nucleotide trp mRNA

Question 18

CAP (catabolite activating protein)is an example of a protein that _______________ transcription.

Accepted Answer

stimulates

Question 19

A unit of gene expression that allows controlled and coordinated expression of a set of proteins is called a(n)__________________.

Accepted Answer

The answer of A unit of gene expression that allows...

Question 20

Briefly explain how attenuation regulates transcription.

Accepted Answer

Attenuation is a prokaryotic mechanism w

Exam 31: The Control of Gene Expression in Prokaryotes

How does the lac repressor inhibit transcription?

Why do many DNA-binding proteins bind as a dimer?

What is a complex community of prokaryotes?

The λ repressor protein blocks transcription of ____________________encoded by the virus.

Many DNA binding proteins,including the CAP and lac repressor,contain a(n)________ in their structure.

What substrate forms a colored product in the presence of β\betaβ -galactosidase?

What kind of expression governs genes that are expressed at all times?

What is the relationship between gene regulation and sequences in the genome?

What is the binding unit for the methionine repressor?

Chemicals released from cells in response to population density and that inhibit gene expression are called

What is the first step in gene expression control?

What name describes the inhibitory effect of glucose,caused by its effect on cAMP levels?

What reaction is carried out by β-galactosidase?

What are biofilms,and why are they medically important?

How does the Cro protein promote the lytic state?

Which of the following is the inducer of the lac operon in cells?

Which of the following is produced when tryptophan levels are low?

CAP (catabolite activating protein)is an example of a protein that _______________ transcription.

A unit of gene expression that allows controlled and coordinated expression of a set of proteins is called a(n)__________________.

Briefly explain how attenuation regulates transcription.

Biochemistry: An Evolving Science

Protein Composition and Structure

Exploring Proteins and Proteomes

DNA, RNA, and the Flow of Genetic Information

Exploring Genes and Genomes

Exploring Evolution and Bioinformatics

Hemoglobin: a Portrait of a Protein in Action

Enzymes: Basic Concepts and Kinetics

Catalytic Strategies

Regulatory Strategies

Carbohydrates

Lipids and Cell Membranes

Membrane Channels and Pumps

Signal-Transduction Pathways

Metabolism: Basic Concepts and Design

Glycolysis and Gluconeogenesis

The Citric Acid Cycle

Oxidative Phosphorylation

The Light Reactions of Photosynthesis

The Calvin Cycle and the Pentose Phosphate Pathway

Glycogen Metabolism

Fatty Acid Metabolism

Protein Turnover and Amino Acid Catabolism

The Biosynthesis of Amino Acids

Nucleotide Biosynthesis

Biosynthesis of Membrane Lipids and Steroids

The Integration of Metabolism

DNA Replication, repair, and Recombination

RNA Synthesis and Processing

Protein Synthesis

The Control of Gene Expression in Eukaryotes

Sensory Systems

The Immune System

Molecular Motors

Drug Development

Filters

What substrate forms a colored product in the presence of $\beta$ -galactosidase?