Question 1

A chemical commonly used to induce the lac operon in laboratory experiments is

Accepted Answer

A)  lactose. 
B)  X-Gal. 
C)  IPTG. 
D)  galactose. 
E)  None of the answers is correct. 
A)  lactose. 
B)  X-Gal. 
C)  IPTG. 
D)  galactose. 
E)  None of the answers is correct.

Question 2

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 3

What are the elements included in the operon model proposed by Jacob and Monod?

Accepted Answer

Their model included a regulat

Question 4

Draw the structure of the lac operon. Identify regions but do not include specific base sequences.

Accepted Answer

The lac operon is a gene regulatory syst

Question 5

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 6

E. coli is the organism in which many _______________ mechanisms were first discovered.

Accepted Answer

The answer of E. coli is the organism in which...

Question 7

How do helix-turn-helix motifs interact with DNA?

Accepted Answer

The first of the two helices b

Question 8

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 9

Which of the following occur in the lytic pathway of bacteriophage infection?

Accepted Answer

A)  Viral particles are released. 
B)  Viral DNA is not expressed. 
C)  Viral genome is carried with bacterial replication. 
D)  Very few viral proteins are produced. 
E)  None of the answers is correct. 
A)  Viral particles are released. 
B)  Viral DNA is not expressed. 
C)  Viral genome is carried with bacterial replication. 
D)  Very few viral proteins are produced. 
E)  None of the answers is correct.

Question 10

Symmetry matching (an inverted repeat) is a common theme in

Accepted Answer

A)  DNA-protein interactions. 
B)  mRNA modification signals. 
C)  ribosome binding to DNA. 
D)  tRNA recognition. 
E)  None of the answers is correct. 
A)  DNA-protein interactions. 
B)  mRNA modification signals. 
C)  ribosome binding to DNA. 
D)  tRNA recognition. 
E)  None of the answers is correct.

Question 11

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 12

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

Accepted Answer

The 2-fold axis of s

Question 13

Which of the following contributes to the attenuation of the trp mRNA transcript?

Accepted Answer

A)  high levels of tryptophan 
B)  plentiful amounts of trp tRNA 
C)  formation of a stem-loop structure at the 5' end of the attenuator region 
D)  uninterrupted synthesis of the leader peptide 
E)  All of the answers are correct. 
A)  high levels of tryptophan 
B)  plentiful amounts of trp tRNA 
C)  formation of a stem-loop structure at the 5' end of the attenuator region 
D)  uninterrupted synthesis of the leader peptide 
E)  All of the answers are correct.

Question 14

Bacterial cells produce a truncated trp mRNA when cellular levels of tryptophan are __________.

Accepted Answer

The answer of Bacterial cells produce a truncated trp mRNA...

Question 15

The λ repressor protein promotes transcription of ________________ encoded by the virus when λ repressor levels are relatively low.

Accepted Answer

λ represso

Question 16

Which of the following conditions leads to the lysogenic state?

Accepted Answer

A)  repressor high, Cro high 
B)  repressor low, Cro low 
C)  repressor high, Cro low 
D)  repressor low, Cro high 
E)  None of the answers is correct. 
A)  repressor high, Cro high 
B)  repressor low, Cro low 
C)  repressor high, Cro low 
D)  repressor low, Cro high 
E)  None of the answers is correct.

Question 17

Is it likely that the DNA binding sites for a repressor evolved from a common ancestor?

Accepted Answer

No. The sites are small and va

Question 18

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 19

In the helix-turn-helix motif of DNA binding proteins, the amino acid side chains of one helix bind to the __________________ and the other to the _________________.

Accepted Answer

major groo

Question 20

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.

Exam 31: The Control of Gene Expression in Prokaryotes

A chemical commonly used to induce the lac operon in laboratory experiments is

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

What are the elements included in the operon model proposed by Jacob and Monod?

Draw the structure of the lac operon. Identify regions but do not include specific base sequences.

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

E. coli is the organism in which many _______________ mechanisms were first discovered.

How do helix-turn-helix motifs interact with DNA?

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

Which of the following occur in the lytic pathway of bacteriophage infection?

Symmetry matching (an inverted repeat) is a common theme in

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

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

Which of the following contributes to the attenuation of the trp mRNA transcript?

Bacterial cells produce a truncated trp mRNA when cellular levels of tryptophan are __________.

The λ repressor protein promotes transcription of ________________ encoded by the virus when λ repressor levels are relatively low.

Which of the following conditions leads to the lysogenic state?

Is it likely that the DNA binding sites for a repressor evolved from a common ancestor?

How does the lac repressor inhibit transcription?

In the helix-turn-helix motif of DNA binding proteins, the amino acid side chains of one helix bind to the __________________ and the other to the _________________.

What is the first step in gene expression control?

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

Oxidative Phosphorylation

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

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

In the helix-turn-helix motif of DNA binding proteins, the amino acid side chains of one helix bind to the __ and the other to the _.