Translation, Protein Synthesis, Antibiotics and Protein Synthesis Control - Exam Questions Flashcards
What is the start codon?
AUG
What is the total number of triplet codons?
64
Where does the amino acid attach to its tRNA?
At the 3’ end
What does the structure of tRNA resemble?
A cloverleaf
What sequence does the 3’ end of tRNA terminate with?
CCA-OH
What is wobble pairing?
The pairing of mRNA bases with non-complementary tRNA bases.
The prokaryotic ribosome:
a. is an 80S complex
b. is made of tow large and two small subunits
c. is identical to the eukaryotic ribosome
d. contains 23S, 5S and 16S rRNA subunits
e. is a protein heterodimer
d. The prokaryotic ribsome contains 23S, 5S and 16S rRNA subunits.
What amino acid does the initiator tRNA carry?
Formylmethionine
fmet
Initiation of transcription in prokaryotes requires:
a. energy from ATP hydrolysis
b. IF1, IF2-GTP, IF3
c. the two RNA subunits to join together priod to tRNA or mRNA binding
d. ATP, UTP, GTP, CTP
e. methionine-tRNAmet
b. Initiation of transcription in prokaryotes requires IF1. IF2-GTP and IF3
What does mRNA bind to on ribosome?
the 30S subunit
The Shine-Dalgarno Sequence…
…on mRNA binds rRNA to ensure in-frame translation
During elongation, activate amino acid:
a. binds to GTP and enters the E site
b. binds to IF2-GTP and enters the P site
c. binds to EF-Tu GTP and enters the A site
d. binds to GTP and enters the P site
e. binds to EF-G GTP and enters the P site
c. During elongation, the activated amino acid binds to EF-Tu GTP and enters the A site
GTP hydrolysis provides energy for:
a. initiation and translocation
b. peptide bond formation and translocation
c. activated amino acid binding and peptide bond formation
d. activated amino acid binding and translocation
e. activated amino acid binding and discharge of rRNA
b. GTP hydrolysis provides the energy for peptide bond formation and translocation
Translocation requires the binding or:
a. EF-Tu
b. RF1
c. IF3
d. EF-G
e. IF1
d. Translocation requires binding of EF-G
Termination is initiated when the stop codon:
a. binds to the A site
b. is translated
c. binds to release factor
d. binds to tRNA
e. binds to the P site
c. Termination is initiated when the STOP codon binds to release factor
What are the STOP codons?
UAA, UAG, UGA
Prokaryotic RNA:
a. has a 5’ cap
b. has a poly A tail
c. contains introns
d. can code for several proteins
e. contains no untranslated sequence
d. Prokaryotic RNA can code for several proteins
Disassembly of the ribosome complex requires:
a. IF3, ribosomal recycling factor, GTP hydrolysis
b. RF1, RF2, ribosomal recycling factor
c. release factor, ribosomal recycling factor, IF1
d. GTP hydrolysis, IF1, IF2
e. GDP, ribosomal recycling factor, RF1
a. Disassembly of the ribosome complex requires IF3, ribosomal recyling factor, GTP hydrolysis
What are the ribosome and subunits in eukaryotes?
80S ribosome = 40S +60S subunits
The antibiotic actinomycin
a. inhibits DNA-dependent RNA synthesis by binding to DNA at the
transcription initiation complex
b. inhibits DNA-dependent RNA synthesis by binding to RNA
polymerase
c. affects initiation at the 30S subunit and causes misreading of codons
d. binds to the 50S subunit and prevents translocation
e. binds to the 50S subunit and inhibits peptidyl transferase
a. Actinomycin is a bacteria that inhibits DNA-dependent RNA synthesis by binding to DNA at the transcription initiation complex
Tetracycline antibiotics
a. inhibit DNA-dependent RNA synthesis by binding to DNA at the
transcription initiation complex
b. affect initiation at the 30S subunit and cause misreading of codons
c. inhibit binding of aminoacyl-tRNAs to the ribosome
d. bind to the 50S subunit and prevents translocation
e. bind to the 50S subunit and inhibits peptidyl transferase
c. Tetracycline inhibits binding of aminoacyl-tRNAs to the ribosome
The antibiotic streptomycin
a. inhibits DNA-dependent RNA synthesis by binding to DNA at the
transcription initiation complex
b. inhibits DNA-dependent RNA synthesis by binding to RNA
polymerase
c. affects initiation at the 30S subunit and causes misreading of codons
d. binds to the 50S subunit and prevents translocation
e. binds to the 50S subunit and inhibits peptidyl transferase
c. Streptomycin affects initiation at the 30S subunit and causes misreading of codons.
The antibiotic rifamycin
a. inhibits DNA-dependent RNA synthesis by binding to RNA
polymerase
b. affects initiation at the 30S subunit and causes misreading of codons
c. binds to the 50S subunit and prevents translocation
d. binds to the 50S subunit and inhibits peptidyl transferase
e. inhibits binding of aminoacyl-tRNAs to the ribosome
a. Rifamycin inhibits DNA-dependent RNA synthesis by binding to RNA polymerase.
The antibiotic chloramphenicol
a. inhibits DNA-dependent RNA synthesis by binding to DNA at the
transcription initiation complex
b. inhibits DNA-dependent RNA synthesis by binding to RNA
polymerase
c. affects initiation at the 30S subunit and causes misreading of codons
d. binds to the 50S subunit and prevents translocation
e. binds to the 50S subunit and inhibits peptidyl transferase
e. Chloramphenicol binds to the 50S subunit and inhibits peptidyl tranferase
