Question 1

Write the sequence of the messenger RNA molecule synthesized from a DNA template strand having the sequence:
(5')ATCGTACCGTTA(3')

Accepted Answer

To write the sequence of the messenger R

Question 2

In the synthesis of the 5' cap of mRNA, what enzyme classes are used at each step?

Accepted Answer

The synthesis of the 5' cap structure of

Question 3

Which statement is FALSE with respect to different $\sigma$ (sigma) subunits in bacterial RNA polymerase?

Accepted Answer

A)  Specific amino acids in $\sigma$ subunits will interact with the polymerase. 
B)  $\sigma$ subunits will specifically interact with DNA sequences spanning approximately three turns of the helix. 
C)  $\sigma$ subunits interact with both DNA and the RNA polymerase in the elongation form. 
D)  Multiple $\sigma$ subunits exist in E. coli. 
E)  The binding of NusA is competitive with the binding of $\sigma$ subunits in E. coli. 
A)  Specific amino acids in $\sigma$ subunits will interact with the polymerase. 
B)  $\sigma$ subunits will specifically interact with DNA sequences spanning approximately three turns of the helix. 
C)  $\sigma$ subunits interact with both DNA and the RNA polymerase in the elongation form. 
D)  Multiple $\sigma$ subunits exist in E. coli. 
E)  The binding of NusA is competitive with the binding of $\sigma$ subunits in E. coli.

Question 4

RNA polymerase:

Accepted Answer

A)  binds tightly to a region of DNA thousands of base pairs away from the DNA to be transcribed. 
B)  can synthesize RNA chains without a primer. 
C)  has a subunit called $\lambda$
 (lambda), which acts as a proofreading ribonuclease. 
D)  separates DNA strands throughout a long region of DNA (up to thousands of base pairs), then copies one of them. 
E)  synthesizes RNA chains in the 3' $\rightarrow$ 5' direction. 
A)  binds tightly to a region of DNA thousands of base pairs away from the DNA to be transcribed. 
B)  can synthesize RNA chains without a primer. 
C)  has a subunit called $\lambda$
 (lambda), which acts as a proofreading ribonuclease. 
D)  separates DNA strands throughout a long region of DNA (up to thousands of base pairs), then copies one of them. 
E)  synthesizes RNA chains in the 3' $\rightarrow$ 5' direction.

Question 5

Compare and contrast $\rho$-dependent and $\rho$-independent termination of transcription in prokaryotes.

Accepted Answer

In prokaryotes, transcription terminatio

Question 6

Which polymerase does NOT require a template?

Accepted Answer

A)  RNA Pol I 
B)  RNA Pol II 
C)  reverse transcriptase 
D)  polyadenylate polymerase 
E)  RNA replicase 
A)  RNA Pol I 
B)  RNA Pol II 
C)  reverse transcriptase 
D)  polyadenylate polymerase 
E)  RNA replicase

Question 7

In eukaryotic splicing, U1-snRNP:

Accepted Answer

A)  is made entirely of RNA. 
B)  is a component of the active splicesosome. 
C)  is complementary to the 5' splice site for the intron. 
D)  becomes covalently attached to a lariat intermediate. 
E)  dissociates from the spliceosomal complex after lariat formation. 
A)  is made entirely of RNA. 
B)  is a component of the active splicesosome. 
C)  is complementary to the 5' splice site for the intron. 
D)  becomes covalently attached to a lariat intermediate. 
E)  dissociates from the spliceosomal complex after lariat formation.

Question 8

Retroviral genomes tend to mutate at a very high rate. What statement BEST explains this observation?

Accepted Answer

A)  The RNA genome is highly susceptible to chemical damage. 
B)  Specific enzymes in cells will modify the genome as a protection against infection. 
C)  RNA phosphodiester bonds will tend to hydrolyze spontaneously. 
D)  The virus changes the sequence to prevent antibody binding to the viral genome. 
E)  Reverse transcriptase lacks a 3' to 5'exonuclease activity. 
A)  The RNA genome is highly susceptible to chemical damage. 
B)  Specific enzymes in cells will modify the genome as a protection against infection. 
C)  RNA phosphodiester bonds will tend to hydrolyze spontaneously. 
D)  The virus changes the sequence to prevent antibody binding to the viral genome. 
E)  Reverse transcriptase lacks a 3' to 5'exonuclease activity.

Question 9

Processing of a primary mRNA transcript in a eukaryotic cell does NOT normally involve:

Accepted Answer

A)  attachment of a long poly(
A)  sequence at the 3' end. 
B)  conversion of normal bases to modified bases, such as inosine and pseudouridine. 
C)  excision of intervening sequences (introns). 
D)  joining of exons. 
E)  methylation of one or more guanine nucleotides at the 5' end. 
A)  attachment of a long poly(
A)  sequence at the 3' end. 
B)  conversion of normal bases to modified bases, such as inosine and pseudouridine. 
C)  excision of intervening sequences (introns). 
D)  joining of exons. 
E)  methylation of one or more guanine nucleotides at the 5' end.

Question 10

The sigma factor of E. coli RNA polymerase:

Accepted Answer

A)  associates with the promoter before binding core enzyme. 
B)  combines with the core enzyme to confer specific binding to a promoter. 
C)  is inseparable from the core enzyme. 
D)  is required for termination of an RNA chain. 
E)  will catalyze synthesis of RNA from both DNA template strands in the absence of the core enzyme. 
A)  associates with the promoter before binding core enzyme. 
B)  combines with the core enzyme to confer specific binding to a promoter. 
C)  is inseparable from the core enzyme. 
D)  is required for termination of an RNA chain. 
E)  will catalyze synthesis of RNA from both DNA template strands in the absence of the core enzyme.

Question 11

What statement is NOT true regarding retroviral reverse transcriptase and eukaryotic DNA polymerase  $\delta$ ?

Accepted Answer

A)  Both enzymes require nucleic acid templates. 
B)  Both enzymes include proof-reading functions. 
C)  Both enzymes use dNTPs as substrates for synthesis. 
D)  Both enzymes require metal cofactors. 
E)  All of the statements are true. 
A)  Both enzymes require nucleic acid templates. 
B)  Both enzymes include proof-reading functions. 
C)  Both enzymes use dNTPs as substrates for synthesis. 
D)  Both enzymes require metal cofactors. 
E)  All of the statements are true.

Question 12

What is a telomere? Describe the key features of its structure. What is unusual about the structure and/or mechanism of action of telomerase?

Accepted Answer

A telomere is a region of repetitive nuc

Question 13

Which compound is NOT a posttranscriptional modification in mRNA or tRNA?

Accepted Answer

A)  4-thiouridine 
B)  pseudouridine 
C)  dihydrouridine 
D)  ribouridine 
E)  ribothymidine 
A)  4-thiouridine 
B)  pseudouridine 
C)  dihydrouridine 
D)  ribouridine 
E)  ribothymidine

Question 14

Which compound is NOT part of miRNA formation?

Accepted Answer

A)  pri-miRNA 
B)  pre-miRNA 
C)  Dicer 
D)  RISC 
E)  pseudouridine 
A)  pri-miRNA 
B)  pre-miRNA 
C)  Dicer 
D)  RISC 
E)  pseudouridine

Question 15

Which statement is FALSE regarding transcription at RNA polymerase II promoters?

Accepted Answer

A)  Transcription requires binding of TBP to the -10 promoter element. 
B)  TFIIB binds TBP and recruits TFIIF that directs RNA polymerase II to the promoter. 
C)  TFIIH unwinds the DNA and phosphorylates the CTD of RNA polymerase II. 
D)  TFIIH subunits contribute to a nucleotide-excision repair process. 
E)  During the elongation phase, elongation factors suppress RNA polymerase II pausing and coordinate protein-protein interactions. 
A)  Transcription requires binding of TBP to the -10 promoter element. 
B)  TFIIB binds TBP and recruits TFIIF that directs RNA polymerase II to the promoter. 
C)  TFIIH unwinds the DNA and phosphorylates the CTD of RNA polymerase II. 
D)  TFIIH subunits contribute to a nucleotide-excision repair process. 
E)  During the elongation phase, elongation factors suppress RNA polymerase II pausing and coordinate protein-protein interactions.

Question 16

Below, an RNA molecule is being transcribed from a strand of DNA. Indicate the 5' and 3' ends of the RNA molecule and of the strand of DNA that is complementary to the RNA molecule. In which direction is synthesis occurring?

Accepted Answer

The answer of Below, an RNA molecule is being transcribed...

Question 17

AZT is one drug used as an HIV inhibitor. How does it specifically inhibit viral replication?

Accepted Answer

A)  AZT is not taken up by human cells. 
B)  AZT binds to human polymerases with lower affinity than to viral reverse transcriptase. 
C)  AZT cannot be phosphorylated to a triphosphate. 
D)  AZT only inhibits active transcription and not DNA replication. 
E)  AZT inhibits viral assembly and packing. 
A)  AZT is not taken up by human cells. 
B)  AZT binds to human polymerases with lower affinity than to viral reverse transcriptase. 
C)  AZT cannot be phosphorylated to a triphosphate. 
D)  AZT only inhibits active transcription and not DNA replication. 
E)  AZT inhibits viral assembly and packing.

Question 18

Which process is involved in generating the different forms of the apoB gene product in liver and intestines?

Accepted Answer

A)  alternative 5' splice-site choice 
B)  alternative 3' splice-site choice 
C)  a C $\rightarrow$ U deamination 
D)  All of these processes are involved. 
E)  None of these processes is involved. 
A)  alternative 5' splice-site choice 
B)  alternative 3' splice-site choice 
C)  a C $\rightarrow$ U deamination 
D)  All of these processes are involved. 
E)  None of these processes is involved.

Question 19

Describe in words (not using structures) the important features of the structures present on the 5' and 3' ends of mature (processed) eukaryotic mRNAs.

Accepted Answer

The 5' end of mature eukaryotic mRNAs co

Question 20

Which eukaryotic transcription factor has helicase activity?

Accepted Answer

A)  TFIIA 
B)  TFIIB 
C)  TFIIF 
D)  TFIIH 
E)  TBP 
A)  TFIIA 
B)  TFIIB 
C)  TFIIF 
D)  TFIIH 
E)  TBP

Exam 26: RNA Metabolism

Write the sequence of the messenger RNA molecule synthesized from a DNA template strand having the sequence: (5')ATCGTACCGTTA(3')

In the synthesis of the 5' cap of mRNA, what enzyme classes are used at each step?

Which statement is FALSE with respect to different σ\sigmaσ (sigma) subunits in bacterial RNA polymerase?

RNA polymerase:

Compare and contrast ρ\rhoρ -dependent and ρ\rhoρ -independent termination of transcription in prokaryotes.

Which polymerase does NOT require a template?

In eukaryotic splicing, U1-snRNP:

Retroviral genomes tend to mutate at a very high rate. What statement BEST explains this observation?

Processing of a primary mRNA transcript in a eukaryotic cell does NOT normally involve:

The sigma factor of E. coli RNA polymerase:

What statement is NOT true regarding retroviral reverse transcriptase and eukaryotic DNA polymerase δ\deltaδ ?

What is a telomere? Describe the key features of its structure. What is unusual about the structure and/or mechanism of action of telomerase?

Which compound is NOT a posttranscriptional modification in mRNA or tRNA?

Which compound is NOT part of miRNA formation?

Which statement is FALSE regarding transcription at RNA polymerase II promoters?

Below, an RNA molecule is being transcribed from a strand of DNA. Indicate the 5' and 3' ends of the RNA molecule and of the strand of DNA that is complementary to the RNA molecule. In which direction is synthesis occurring?

AZT is one drug used as an HIV inhibitor. How does it specifically inhibit viral replication?

Which process is involved in generating the different forms of the apoB gene product in liver and intestines?

Describe in words (not using structures) the important features of the structures present on the 5' and 3' ends of mature (processed) eukaryotic mRNAs.

Which eukaryotic transcription factor has helicase activity?

The Foundations of Biochemistry

Water

Amino Acids, Peptides, and Proteins

The Three-Dimensional Structure of Proteins

Protein Function

Enzymes

Carbohydrates and Glycobiology

Nucleotides and Nucleic Acids

DNA-Based Information Technologies

Lipids

Biological Membranes and Transport

Biosignaling

Bioenergetics and Biochemical Reaction Types

Glycolysis, Gluconeogenesis, and the Pentose Phosphate Pathway

Principles of Metabolic Regulation

The Citric Acid Cycle

Fatty Acid Catabolism

Amino Acid Oxidation and the Production of Urea

Oxidative Phosphorylation and Photophosphorylation

Carbohydrate Biosynthesis in Plants and Bacteria

Lipid Biosynthesis

Biosynthesis of Amino Acids, Nucleotides, and Related Molecules

Hormonal Regulation and Integration of Mammalian Metabolism

Genes and Chromosomes

DNA Metabolism

Protein Metabolism

Regulation of Gene Expression

Filters

Which statement is FALSE with respect to different $\sigma$ (sigma) subunits in bacterial RNA polymerase?

Compare and contrast $\rho$ -dependent and $\rho$ -independent termination of transcription in prokaryotes.

What statement is NOT true regarding retroviral reverse transcriptase and eukaryotic DNA polymerase $\delta$ ?