Deck 8: Transcription, Translation, and Bioinformatics

Question 1

The average half-life for mRNA in E. coli is:

A) 10-30 seconds
B) 30-60 seconds
C) 1-3 minutes
D) 3-5 minutes
E) 5-10 minutes

Answer 1

C

Question 2

Transcription occurs in the __________ and translation occurs in the __________ of a eukaryotic cell.

A) nucleoid; cytoplasm
B) cytoplasm; cytoplasm
C) nucleus; cytoplasm
D) nucleus; nucleus
E) nucleoid; nucleoid

Answer 2

C

Question 3

Which of the following can cause transcription to end?

A) stem and loop
B) sigma
C) stop codon
D) rho
E) more than one of the above

Answer 3

E

Question 4

The semisynthetic derivative of rifamycin is __________.

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

Question 5

The "housekeeping" sigma factor in E. coli is:

A) sigma-28
B) sigma-38
C) sigma-54
D) sigma-70
E) sigma-97

Question 6

The unusual bases found in tRNA are poor substrates for __________.

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

Question 7

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

A) The RNA polymerase holoenzyme binds.
B) GTP hydrolysis catalyzes bubble formation.
C) The promoter unwinds.
D) The first rNTP is usually a purine.
E) Position +1 marks the start of the gene.

Question 8

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

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

Question 9

An enzyme complex called RNA polymerase, also known as __________-dependent __________ polymerase, carries out the process of transcription.

A) RNA; DNA
B) transcription; DNA
C) transcription; RNA
D) DNA; RNA
E) translation; RNA

Question 10

What do codons and anticodons have in common?

A) They are part of tRNA.
B) They are sequences of DNA 3 nucleotides long.
C) They are identical RNA sequences.
D) They are complementary RNA sequences.
E) None of the above.

Question 11

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

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

Question 12

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

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

Question 13

Which drug interferes with transcription in prokaryotes?

A) chloramphenicol
B) erythromycin
C) rifamycin B
D) streptomycin
E) tetracycline

Question 14

During transcription of the __________ genes, normal, unmodified bases are incorporated, but some of these are modified later by specific enzymes.

A) tRNA
B) rRNA
C) mRNA
D) sRNA
E) catalytic RNA

Question 15

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

A) the RNA polymerase holoenzyme
B) binding of RNA polymerase to the beginning of the gene
C) melting of the helix
D) synthesis of a primer
E) base pairing of the first nucleotide of the RNA

Question 16

Without __________, the core RNA polymerase binds and releases DNA at random.

A) sigma factor
B) initiation factor
C) Shine-Dalgarno sequence
D) peptidyltransferase
E) release factor

Question 17

__________ is normally read as a stop codon but encodes tryptophan in vertebrate mitochondria.

A) AUG
B) UCA
C) UAC
D) UGA
E) AUC

Question 18

Rho functions in:

A) protein degradation
B) protein secretion
C) initiation of translation
D) termination of transcription
E) release of ribosomes from the mRNA

Question 19

__________ RNA polymerase plus sigma factor together are called __________.

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

Question 20

A __________ sequence consists of the most likely base (or bases) at each position.

A) consensus
B) promoter
C) Shine-Dalgarno
D) regulatory
E) termination

Question 21

A __________ RNA is a single RNA molecule that contains information from several contiguous genes.

A) cistronic
B) transfer
C) polycistronic
D) ribosomal
E) messenger

Question 22

The typical E. coli cell has approximately how many ribosomes?

A) 100
B) 300
C) 1,000
D) 18,000
E) 100,000

Question 23

Different __________ can bind simultaneously to the start of each cistron within a polycistronic mRNA.

A) genes
B) proteins
C) polymerases
D) ribosomes
E) RNases

Question 24

Genes encoding the form of antibiotic resistance involving an efflux transport system are commonly encoded on __________.

A) chromosomes
B) plasmids
C) bacteriophage
D) transposons
E) sigma

Question 25

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

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 26

Several different antibiotics have been isolated from.

A) E. coli
B) Streptomyces
C) Mycoplasma
D) Mycobacterium
E) Streptococcus

Question 27

Which form of RNA has the task of unsticking stuck ribosomes?

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

Question 28

Post-translational modification may involve:

A) adenylylation
B) phosphorylation
C) acetylation
D) all of the above
E) none of the above

Question 29

What is the significance of the Shine-Dalgarno sequence?

A) It is the site where RNA polymerase binds to begin transcription.
B) It is the site where ribosomes bind to begin translation.
C) It is the site where DNA polymerase binds to begin chromosome replication.
D) It is the site where the tRNA binds to the mRNA in translation.
E) It is the site where DNA polymerase begins synthesis of the Okazaki fragments on the lagging strand.

Question 30

Which RNA species is a component of the 30S subunit of the ribosome?

A) 5S RNA
B) 16S RNA
C) 23S RNA
D) tRNA
E) mRNA

Question 31

__________ serves as a molecular clock that measures the approximate time since two species diverged.

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

Question 32

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

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

Question 33

Peptide bond formation effectively transfers the peptide from the tRNA in the __________ to tRNA in the __________.

A) P-site; A-site
B) A-site; P-site
C) P-site; E-site
D) E-site; A-site
E) E-site; P-site

Question 34

What is the importance of the stop codon UAG?

A) It tells the DNA polymerase to stop replicating the chromosome.
B) It tells the RNA polymerase to stop transcribing the chromosome.
C) It tells the tRNA to stop transcribing the DNA.
D) It tells the ribosome to stop translating the mRNA.
E) It signals the end of the operon.

Question 35

The energy source utilized by the elongation factors EF-G and EF-Tu is:

A) proton motive force
B) ATP hydrolysis
C) GTP hydrolysis
D) phosphoenolpyruvate hydrolysis
E) none is required

Question 36

The charging of tRNAs is carried out by a set of enzymes called __________ transferases.

A) ribozymes
B) aminoacyl-tRNA
C) peptidyl
D) proteases
E) polymerases

Question 37

Which of the following are required for the termination of translation?

A) sRNAs
B) degrons
C) tolC proteins
D) release factors
E) ubiquitins

Question 38

Peptidyl transferase is present in the __________ ribosomal subunit.

A) 30S
B) 50S
C) 5S
D) 16S
E) 80S

Question 39

The __________ of transcription and translation helps microbes rapidly adjust gene expression to changes in their environment.

A) coupling
B) separation
C) processes
D) slowing
E) pausing

Question 40

Which of the following is a ribozyme?

A) Clp protease
B) release factor
C) trigger factor
D) peptidyl transferase
E) aminoacyl-tRNA transferase

Question 41

Define "half-life" in terms of mRNA. Biologically, why is it important that the half-life of mRNA be the shortest of the RNAs? What chemically leads to a longer half-life for tRNAs and rRNAs?

Question 42

Which of the following is an example of a heat shock protein?

A) Clp protease
B) tolC
C) SecB
D) Gro EL
E) Rho

Question 43

The term __________ is used to describe movement of a protein out of the cytoplasm.

A) "export"
B) "import"
C) "translocation"
D) "transport"
E) "secretion"

Question 44

Name two antibiotics that affect transcription and explain their mode of action.

Question 45

How do sigma factors regulate major physiological responses?

Question 46

__________ controls protein turnover by closely regulating the degradation of specific proteins.

A) Ubiquitination
B) Half-life
C) Amino acid sequence
D) Tertiary structure
E) Protease

Question 47

Gram-negative microbes are surrounded by two layers of __________, between which lies a periplasmic space.

A) peptidoglycan
B) membrane
C) lipopolysaccharide
D) cellulose
E) chitin

Question 48

Describe the experiment utilizing an E. coli cell lysate that was used to figure out the genetic code.

Question 49

What is a chimeric RNA pol and how was it used to determine the mechanism of antibiotic resistance in RNA pol?

Question 50

Similar genes within the same organism that have different functions are referred to as:

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

Question 51

What are the functions of the different types of RNA molecules?

Question 52

How does the mRNA referred to as the sense strand compare to the template and nontemplate DNA strand?

Question 53

Which of the following uses the proton motive force as its energy source?

A) signal recognition particle
B) SecYEG translocon
C) SecA ATPase
D) twin arginine translocase
E) type I protein secretion

Question 54

Explain the process of transcription initiation.

Question 55

Signal sequences are found:

A) in the 30S ribosomal subunit
B) in the 50S ribosomal subunit
C) at the N-terminal end of a protein
D) at the C-terminal end of a mRNA
E) upstream of the promoter

Question 56

In eukaryotes, protein degradation occurs through organelles called __________.

A) proteases
B) lysosomes
C) RNases
D) proteasomes
E) vacuoles

Question 57

The general secretion complex known as the SecYEG translocon is found in the:

A) nucleus
B) inner membrane
C) cell wall
D) periplasmic space
E) outer membrane

Question 58

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

Question 59

Where is the Shine-Dalgarno sequence located and what is it responsible for?

Question 60

Which of the following terms refers to a discipline involving comparison of genes of different species?

A) annotation
B) bioinformatics
C) ORFs
D) sequence homology
E) computer analysis

Question 61

Since ribosomes do not translate to the end of the mRNA, what causes translation to end?

Question 62

What does it mean to say that transcription and translation are coupled and what are some of the potential problems with this?

Question 63

Every mRNA has three possible reading frames. How does the ribosome find the correct reading frame?

Question 64

Why is protein degradation necessary to maintain cellular health?

Question 65

Name two antibiotics that affect translation and explain their mode of action.

Question 66

If an mRNA has been damaged so that it no longer has a stop codon, what happens to the ribosome and how is this problem solved?

Question 67

Eukaryotes and the archaea contain proteasomes. Compare and contrast these proteasomes in terms of structure and function.

Question 68

How are folded and unfolded proteins moved from the cytoplasm to the periplasm?

Question 69

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

Question 70

What specifically about eukaryotes makes bioinformatic analysis more complicated?