Question 1

How do sigma factors in a bacterium such as E. coli regulate major physiological responses?

Accepted Answer

Any one species such as E. coli can make several different sigma factors that help RNA polymerase find the beginnings of different subsets of genes. One key sigma factor is rpoD or sigma 70. This sigma factor is involved in recognizing "housekeeping" genes that are always needed. The different sigma factors help RNA polymerase recognize different classes of promoters and control genes involved in nitrogen metabolism, flagellar synthesis, heat, stress, starvation, sporulation, and other physiological responses. Organisms have protein sensors that monitor the environment. When necessary, they direct the cell to increase synthesis of the appropriate sigma factor. Accumulation of specialty sigma factors dislodge other sigma factors from RNA polymerase and redirect RNA polymerase to promoters for genes that can be used to solve the problem sensed by the protein sensors. The cell can control physiological responses by regulating when a specific sigma factor accumulates.

Question 2

Using the genetic code shown below, find the correct start and stop codons. Which of the following peptides might this message code for?  
5'-GAGUUAUGCACGGGUUCUAUGUGUAG-3'

Accepted Answer

A)  GLU-LEU-CYS-MET-GLY-SER-MET-CYS 
B)  MET-GLY-SER-MET-CYS 
C)  MET-HIS-GLY-PHE-TYR-VAL 
D)  MET-CYS-ILE-LEU-GLY-THR-TYR 
E)  ASP-VAL-TYR-LEU-GLY-TYR-VAL-LEU 
A)  GLU-LEU-CYS-MET-GLY-SER-MET-CYS 
B)  MET-GLY-SER-MET-CYS 
C)  MET-HIS-GLY-PHE-TYR-VAL 
D)  MET-CYS-ILE-LEU-GLY-THR-TYR 
E)  ASP-VAL-TYR-LEU-GLY-TYR-VAL-LEU C

Question 3

Molecules of sRNA do not encode proteins but are used to ________ the stability or translation of specific mRNAs into proteins.

Accepted Answer

A)  start 
B)  regulate 
C)  stop 
D)  speed up 
E)  slow down 
A)  start 
B)  regulate 
C)  stop 
D)  speed up 
E)  slow down B

Question 4

SRP stands for ________, and it plays a role in ________.

Accepted Answer

A)  secretion recognition particle; refolding 
B)  secretion ribosomal particle; refolding 
C)  signal recognition particle; refolding 
D)  secretion ribosomal particle; secretion 
E)  signal recognition particle; secretion 
A)  secretion recognition particle; refolding 
B)  secretion ribosomal particle; refolding 
C)  signal recognition particle; refolding 
D)  secretion ribosomal particle; secretion 
E)  signal recognition particle; secretion

Question 5

Explain how a type I secretion system works. Are the secreted proteins ever in periplasmic space?

Accepted Answer

A type I secretion system is comprised o

Question 6

Which of the following is NOT an example of a heat-shock protein?

Accepted Answer

A)  trigger factor 
B)  GroES 
C)  GroEL 
D)  Clp protease 
E)  DnaK 
A)  trigger factor 
B)  GroES 
C)  GroEL 
D)  Clp protease 
E)  DnaK

Question 7

The unusual bases found in tRNA are poor substrates for

Accepted Answer

A)  proteases. 
B)  polymerases. 
C)  ribosomes. 
D)  ribozymes. 
E)  RNases. 
A)  proteases. 
B)  polymerases. 
C)  ribosomes. 
D)  ribozymes. 
E)  RNases.

Question 8

Most tRNA molecules begin with a 5' ________ and all end with a 3' ________, to which the amino acids attach.

Accepted Answer

A)  phosphate; hydroxyl 
B)  C; GGA 
C)  G; CCA 
D)  A; TTA 
E)  C; AAT 
A)  phosphate; hydroxyl 
B)  C; GGA 
C)  G; CCA 
D)  A; TTA 
E)  C; AAT

Question 9

Where is fMet used as the N-terminal amino acid? What does that mean for the human immune response?

Accepted Answer

N-formylmethionine (fMet) is important d

Question 10

Genes that have arisen from a duplication within a species and have evolved to carry out different functions are referred to as

Accepted Answer

A)  homologs. 
B)  orthologs. 
C)  paralogs. 
D)  homogenous. 
E)  synonymous. 
A)  homologs. 
B)  orthologs. 
C)  paralogs. 
D)  homogenous. 
E)  synonymous.

Question 11

A researcher is studying transcription and has added a chemical to a transcription experiment using both E. coli and mammalian cells. This chemical inhibits both systems. The chemical is most likely

Accepted Answer

A)  streptomycin. 
B)  rifamycin. 
C)  erythromycin. 
D)  rifampin. 
E)  actinomycin D. 
A)  streptomycin. 
B)  rifamycin. 
C)  erythromycin. 
D)  rifampin. 
E)  actinomycin D.

Question 12

Which drug intercalates into DNA and inhibits transcription in both prokaryotes and eukaryotes?

Accepted Answer

A)  streptomycin 
B)  actinomycin D 
C)  chloramphenicol 
D)  rifampin 
E)  tetracycline 
A)  streptomycin 
B)  actinomycin D 
C)  chloramphenicol 
D)  rifampin 
E)  tetracycline

Question 13

Explain the processes of Rho-dependent and Rho-independent termination of transcription.

Accepted Answer

Rho-dependent termination involves Rho b

Question 14

Which of the following may serve as a molecular clock that measures the approximate time since two related species diverged?

Accepted Answer

A)  tRNA 
B)  mRNA 
C)  rRNA 
D)  sRNA 
E)  tmRNA 
A)  tRNA 
B)  mRNA 
C)  rRNA 
D)  sRNA 
E)  tmRNA

Question 15

________ RNA polymerase plus sigma factor together are called ________.

Accepted Answer

A)  Transcription; translation 
B)  Holoenzyme; core 
C)  Translation; transcription 
D)  Core; holoenzyme 
E)  Ribosome; rRNA 
A)  Transcription; translation 
B)  Holoenzyme; core 
C)  Translation; transcription 
D)  Core; holoenzyme 
E)  Ribosome; rRNA

Question 16

DNA-dependent ________ polymerase makes a copy of DNA that is then used for translation. The process carried out by this enzyme is called ________.

Accepted Answer

A)  RNA; transformation 
B)  protein; transcription 
C)  DNA; transcription 
D)  RNA; transcription 
E)  protein; transposition 
A)  RNA; transformation 
B)  protein; transcription 
C)  DNA; transcription 
D)  RNA; transcription 
E)  protein; transposition

Question 17

Gram-negative microbes are surrounded by two layers of ________, between which lies ________.

Accepted Answer

A)  membrane; periplasm 
B)  membrane; periplasmic space and lipopolysaccharide 
C)  membrane; periplasmic space and peptidoglycan 
D)  lipopolysaccharide; periplasmic space and peptidoglycan 
E)  lipopolysaccharide; peptidoglycan 
A)  membrane; periplasm 
B)  membrane; periplasmic space and lipopolysaccharide 
C)  membrane; periplasmic space and peptidoglycan 
D)  lipopolysaccharide; periplasmic space and peptidoglycan 
E)  lipopolysaccharide; peptidoglycan

Question 18

After ________, each polypeptide must be properly folded and placed at the correct cellular or extracellular location.

Accepted Answer

A)  replication 
B)  transcription 
C)  translation 
D)  degradation 
E)  conjugation 
A)  replication 
B)  transcription 
C)  translation 
D)  degradation 
E)  conjugation

Question 19

What does it mean to say that the genetic code is redundant?

Accepted Answer

A)  There is more than one kind of amino acid in proteins. 
B)  More than one rRNA can bind to the ribosome at the same time. 
C)  A codon is composed of more than one nucleotide. 
D)  More than one codon can specify the same amino acid. 
E)  All products of translation contain a certain minimum number of mistakes, called mutations. 
A)  There is more than one kind of amino acid in proteins. 
B)  More than one rRNA can bind to the ribosome at the same time. 
C)  A codon is composed of more than one nucleotide. 
D)  More than one codon can specify the same amino acid. 
E)  All products of translation contain a certain minimum number of mistakes, called mutations.

Question 20

Which of the following is NOT part of initiation of transcription?

Accepted Answer

A)  -10 and -35 sequences 
B)  binding of RNA polymerase to the beginning of the gene 
C)  melting of the helix 
D)  binding of sigma factor to promoter followed by binding of core RNA polymerase 
E)  base pairing of the first nucleotide of the RNA 
A)  -10 and -35 sequences 
B)  binding of RNA polymerase to the beginning of the gene 
C)  melting of the helix 
D)  binding of sigma factor to promoter followed by binding of core RNA polymerase 
E)  base pairing of the first nucleotide of the RNA

Exam 8: Transcription, Translation, and Bioinformatics

How do sigma factors in a bacterium such as E. coli regulate major physiological responses?

Using the genetic code shown below, find the correct start and stop codons. Which of the following peptides might this message code for? 5'-GAGUUAUGCACGGGUUCUAUGUGUAG-3'

Molecules of sRNA do not encode proteins but are used to ________ the stability or translation of specific mRNAs into proteins.

SRP stands for ________, and it plays a role in ________.

Explain how a type I secretion system works. Are the secreted proteins ever in periplasmic space?

Which of the following is NOT an example of a heat-shock protein?

The unusual bases found in tRNA are poor substrates for

Most tRNA molecules begin with a 5' ________ and all end with a 3' ________, to which the amino acids attach.

Where is fMet used as the N-terminal amino acid? What does that mean for the human immune response?

Genes that have arisen from a duplication within a species and have evolved to carry out different functions are referred to as

A researcher is studying transcription and has added a chemical to a transcription experiment using both E. coli and mammalian cells. This chemical inhibits both systems. The chemical is most likely

Which drug intercalates into DNA and inhibits transcription in both prokaryotes and eukaryotes?

Explain the processes of Rho-dependent and Rho-independent termination of transcription.

Which of the following may serve as a molecular clock that measures the approximate time since two related species diverged?

________ RNA polymerase plus sigma factor together are called ________.

DNA-dependent ________ polymerase makes a copy of DNA that is then used for translation. The process carried out by this enzyme is called ________.

Gram-negative microbes are surrounded by two layers of ________, between which lies ________.

After ________, each polypeptide must be properly folded and placed at the correct cellular or extracellular location.

What does it mean to say that the genetic code is redundant?

Which of the following is NOT part of initiation of transcription?

Microbial Life: Origin and Discovery

Observing the Microbial Cell

Cell Structure and Function

Bacterial Culture, Growth, and Development

Environmental Influences and Control of Microbial Growth

Viruses

Genomes and Chromosomes

Gene Transfer, Mutations, and Genome Evolution

Molecular Regulation

Viral Molecular Biology

Biotechniques and Synthetic Biology

Energetics and Catabolism

Electron Flow in Organotrophy, Lithotrophy, and Phototrophy

Biosynthesis

Food and Industrial Microbiology

Origins and Evolution

Bacterial Diversity

Archaeal Diversity

Eukaryotic Diversity

Microbial Ecology

Microbes in Global Elemental Cycles

Human Microbiota and Innate Immunity

The Adaptive Immune Response

Microbial Pathogenesis

Microbial Diseases

Antimicrobial Therapy

Clinical Microbiology and Epidemiology

Filters

SRP stands for , and it plays a role in .

Most tRNA molecules begin with a 5' and all end with a 3' , to which the amino acids attach.

RNA polymerase plus sigma factor together are called .

DNA-dependent polymerase makes a copy of DNA that is then used for translation. The process carried out by this enzyme is called .

Gram-negative microbes are surrounded by two layers of , between which lies .