Question 1

Inducers for operons are often structurally related to the enzyme substrates of that operon.

Accepted Answer

A) True 
 B)False

Question 2

There is only one sigma subunit, since the same RNA Polymerase must bind to all genes in E. coli.

Accepted Answer

A) True 
 B)False

Question 3

What is the function of the sigma (σ) subunit of RNA polymerase in E. coli?

Accepted Answer

A)  It recognizes promoters where transcription should begin. 
B)  It contains the active site for synthesis of RNA. 
C)  It ensures proper processitvity of the polymerase, so it doesn't stop prematurely. 
D)  It is involved in chain termination. 
E)  It scrunches the DNA 
A)  It recognizes promoters where transcription should begin. 
B)  It contains the active site for synthesis of RNA. 
C)  It ensures proper processitvity of the polymerase, so it doesn't stop prematurely. 
D)  It is involved in chain termination. 
E)  It scrunches the DNA

Question 4

Splicing reactions for exons involve the following mechanisms, except:

Accepted Answer

A)  Small nuclear RNAs 
B)  Ribozymes 
C)  Lariat mechanisms 
D)  Participation of special G residues 
E)  All of these are involved in splicing reactions 
A)  Small nuclear RNAs 
B)  Ribozymes 
C)  Lariat mechanisms 
D)  Participation of special G residues 
E)  All of these are involved in splicing reactions

Question 5

Which of the following is more often associated with transcription being switched off?

Accepted Answer

A)  Presence of histone remodeling complexes SWI/SNF 
B)  Active Histone Acetyltransferase 
C)  Unmethylated cytosines 
D)  Methylated cytosines 
E)  None of these 
A)  Presence of histone remodeling complexes SWI/SNF 
B)  Active Histone Acetyltransferase 
C)  Unmethylated cytosines 
D)  Methylated cytosines 
E)  None of these

Question 6

Which of the conditions would result in the least amount of transcription of the lac operon?

Accepted Answer

A)  I 
B)  II 
C)  III 
D)  IV 
A)  I 
B)  II 
C)  III 
D)  IV

Question 7

Transcription in eukaryotes differs from RNA synthesis in prokaryotes

Accepted Answer

A)  by requiring a primer. 
B)  by simplifying the process with multifunctional enzymes. 
C)  in using more complex σ factors. 
D)  by having multiple RNA polymerases rather than one. 
A)  by requiring a primer. 
B)  by simplifying the process with multifunctional enzymes. 
C)  in using more complex σ factors. 
D)  by having multiple RNA polymerases rather than one.

Question 8

As in prokaryotes, the regulatory regions for eukaryotic genes:

Accepted Answer

A)  may be close to the genes they control 
B)  may be upstream of the genes they control 
C)  may be downstream of the genes they control 
D)  All of these are true 
A)  may be close to the genes they control 
B)  may be upstream of the genes they control 
C)  may be downstream of the genes they control 
D)  All of these are true

Question 9

Which of the following is not a property of the sigma (σ) subunit?

Accepted Answer

A)  It tells the RNA Polymerase where to sit down. 
B)  It helps point the RNA Polymerase in the proper direction. 
C)  It causes the RNA Polymerase to bind tightly to the DNA. 
D)  It stays with the RNA Polymerase throughout synthesis. 
A)  It tells the RNA Polymerase where to sit down. 
B)  It helps point the RNA Polymerase in the proper direction. 
C)  It causes the RNA Polymerase to bind tightly to the DNA. 
D)  It stays with the RNA Polymerase throughout synthesis.

Question 10

A commonly encountered feature of transfer RNA synthesis is

Accepted Answer

A)  the precursor of several tRNA molecules is transcribed in one long polynucleotide sequence 
B)  there is little or no base modification after transcription 
C)  modification of the sugar moiety never takes place 
D)  the covalent binding of tRNA to specific proteins 
A)  the precursor of several tRNA molecules is transcribed in one long polynucleotide sequence 
B)  there is little or no base modification after transcription 
C)  modification of the sugar moiety never takes place 
D)  the covalent binding of tRNA to specific proteins

Question 11

Proteins that recognize DNA with specific base sequences are

Accepted Answer

A)  more likely to bind to the major groove. 
B)  more likely to bind to the minor groove. 
C)  equally likely to bind to the major or minor grooves. 
D)  never occur. 
A)  more likely to bind to the major groove. 
B)  more likely to bind to the minor groove. 
C)  equally likely to bind to the major or minor grooves. 
D)  never occur.

Question 12

Which of the following does not influence the timing of expression of an operon?

Accepted Answer

A)  Repressors 
B)  Co-repressors 
C)  Presence of substrates of the operon which need to be degraded 
D)  Inducers 
E)  All of these influence the timing of expression 
A)  Repressors 
B)  Co-repressors 
C)  Presence of substrates of the operon which need to be degraded 
D)  Inducers 
E)  All of these influence the timing of expression

Question 13

What provides the energy for rho-dependent chain termination?

Accepted Answer

A)  ATP hydrolysis distinct from any incorporation into the chain. 
B)  Nucleotide hydrolysis associated with incorporation into the chain. 
C)  Torsional stress built into the separating DNA strands. 
D)  There is no energy requirement. 
A)  ATP hydrolysis distinct from any incorporation into the chain. 
B)  Nucleotide hydrolysis associated with incorporation into the chain. 
C)  Torsional stress built into the separating DNA strands. 
D)  There is no energy requirement.

Question 14

Ribozymes

Accepted Answer

A)  are more efficient catalysts than protein-based enzymes. 
B)  are involved in protein synthesis. 
C)  always use the same mechanism of catalysis. 
D)  probably evolved later than protein-based enzymes. 
A)  are more efficient catalysts than protein-based enzymes. 
B)  are involved in protein synthesis. 
C)  always use the same mechanism of catalysis. 
D)  probably evolved later than protein-based enzymes.

Question 15

Which of the following is not a characteristic of catabolite activator protein (CAP)?

Accepted Answer

A)  it is a positive regulator of the lac operon 
B)  when the cell has sufficient glucose and lactose, CAP will not be bound to the CAP binding site 
C)  CAP binding near the promoter site depends on CAP complexation with cAMP 
D)  the binding of CAP to DNA requires ATP hydrolysis 
A)  it is a positive regulator of the lac operon 
B)  when the cell has sufficient glucose and lactose, CAP will not be bound to the CAP binding site 
C)  CAP binding near the promoter site depends on CAP complexation with cAMP 
D)  the binding of CAP to DNA requires ATP hydrolysis

Question 16

Which of these terms does not describe the DNA strand used to direct RNA synthesis?

Accepted Answer

A)  Template strand 
B)  Coding strand 
C)  Antisense strand 
D)  Negative or "−" strand 
E)  All these terms describe the DNA strand used to direct RNA synthesis 
A)  Template strand 
B)  Coding strand 
C)  Antisense strand 
D)  Negative or "−" strand 
E)  All these terms describe the DNA strand used to direct RNA synthesis

Question 17

Initiation of RNA biosynthesis involves

Accepted Answer

A)  recognition of the promoter region by the α subunit of RNA polymerase 
B)  conversion of the closed-promoter complex to the open-promoter complex 
C)  binding of one of the α subunits of RNA polymerase to each strand of DNA 
D)  incorporation of four pyrimidine nucleotides in succession 
A)  recognition of the promoter region by the α subunit of RNA polymerase 
B)  conversion of the closed-promoter complex to the open-promoter complex 
C)  binding of one of the α subunits of RNA polymerase to each strand of DNA 
D)  incorporation of four pyrimidine nucleotides in succession

Question 18

How do the core enzyme and the holoenzyme of RNA polymerase differ in E. coli?

Accepted Answer

A)  The holoenzyme includes the sigma (σ) subunit, the core enzyme does not. 
B)  The core enzyme includes the sigma (σ) subunit, the holoenzyme does not. 
C)  The holoenzyme transcribes from an RNA template, the core enzyme from a DNA template. 
D)  The core enzyme transcribes from an RNA template, the holoenzyme from a DNA template. 
A)  The holoenzyme includes the sigma (σ) subunit, the core enzyme does not. 
B)  The core enzyme includes the sigma (σ) subunit, the holoenzyme does not. 
C)  The holoenzyme transcribes from an RNA template, the core enzyme from a DNA template. 
D)  The core enzyme transcribes from an RNA template, the holoenzyme from a DNA template.

Question 19

Which of following statements concerning RNA transcription is false?

Accepted Answer

A)  The release of pyrophosphate from a nucleoside triphosphate drives the reaction. 
B)  RNA is synthesized from the 5' end to the 3' end. 
C)  DNA to RNA base pairing includes A to U and G to C. 
D)  Transcription requires the use of a primer. 
E)  None of these 
A)  The release of pyrophosphate from a nucleoside triphosphate drives the reaction. 
B)  RNA is synthesized from the 5' end to the 3' end. 
C)  DNA to RNA base pairing includes A to U and G to C. 
D)  Transcription requires the use of a primer. 
E)  None of these

Question 20

RNA polymerases from prokaryotes and eukaryotes

Accepted Answer

A)  have sequence homology in catalytic subunits 
B)  have identical σ factors 
C)  differ because there is no analogue to the prokaryotic α subunit in eukaryotes 
D)  have the same number and kind of subunits 
A)  have sequence homology in catalytic subunits 
B)  have identical σ factors 
C)  differ because there is no analogue to the prokaryotic α subunit in eukaryotes 
D)  have the same number and kind of subunits

Exam 11: Transcription of the Genetic Code: Biosynthesis of RNA

Inducers for operons are often structurally related to the enzyme substrates of that operon.

There is only one sigma subunit, since the same RNA Polymerase must bind to all genes in E. coli.

What is the function of the sigma (σ) subunit of RNA polymerase in E. coli?

Splicing reactions for exons involve the following mechanisms, except:

Which of the following is more often associated with transcription being switched off?

Which of the conditions would result in the least amount of transcription of the lac operon?

Transcription in eukaryotes differs from RNA synthesis in prokaryotes

As in prokaryotes, the regulatory regions for eukaryotic genes:

Which of the following is not a property of the sigma (σ) subunit?

A commonly encountered feature of transfer RNA synthesis is

Proteins that recognize DNA with specific base sequences are

Which of the following does not influence the timing of expression of an operon?

What provides the energy for rho-dependent chain termination?

Ribozymes

Which of the following is not a characteristic of catabolite activator protein (CAP)?

Which of these terms does not describe the DNA strand used to direct RNA synthesis?

Initiation of RNA biosynthesis involves

How do the core enzyme and the holoenzyme of RNA polymerase differ in E. coli?

Which of following statements concerning RNA transcription is false?

RNA polymerases from prokaryotes and eukaryotes

Biochemistry and the Organization of Cells

Water: the Solvent for Biochemical Reactions

Amino Acids and Peptides

The Three-Dimensional Structure of Proteins

Protein Purification and Characterization Techniques

The Behavior of Proteins: Enzymes

The Behavior of Proteins: Enzymes, Mechanisms, and Control

Lipids and Proteins Are Associated in Biological Membranes

Nucleic Acids: How Structure Conveys Information

Biosynthesis of Nucleic Acids: Replication

Protein Synthesis: Translation of the Genetic Message

Nucleic Acid Biotechnology Techniques

Viruses, Cancer, and Immunology

The Importance of Energy Changes and Electron Transfer in Metabolism

Carbohydrates

Glycolysis

Storage Mechanisms and Control in Carbohydrate Metabolism

The Citric Acid Cycle

Electron Transport and Oxidative Phosphorylation

Lipid Metabolism

Photosynthesis

The Metabolism of Nitrogen

Integration of Metabolism: Cellular Signaling

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