Question 1

Which of the following best describes the method used for error minimization or proofreading to ensure the correct charging of the tRNAs?

Accepted Answer

A) The enzymes catalyzing the addition always proofread after the first step. 
B) The enzymes catalyzing the addition always proofread after the second step. 
C) Some of the enzymes catalyzing the addition proofread after the first step,some after the second. 
D) Ribosomes themselves proofread the linkage when the AA-tRNA reaches the A site. 
E) No proofreading of this process occurs. 
A) The enzymes catalyzing the addition always proofread after the first step. 
B) The enzymes catalyzing the addition always proofread after the second step. 
C) Some of the enzymes catalyzing the addition proofread after the first step,some after the second. 
D) Ribosomes themselves proofread the linkage when the AA-tRNA reaches the A site. 
E) No proofreading of this process occurs. C

Question 2

During translation,translocation of the ribosome is driven by which of the following?

Accepted Answer

A) ATP → ADP + Pi 
B) ATP → AMP + PPi 
C) GTP → GDP + Pi 
D) GTP → GMP + PPi 
E) Release of the tRNA in the P site 
A) ATP → ADP + Pi 
B) ATP → AMP + PPi 
C) GTP → GDP + Pi 
D) GTP → GMP + PPi 
E) Release of the tRNA in the P site C

Question 3

Matching
Choose the correct answer from the list.Not all the answers will be used.

-A mutation that converts an aminoacyl-coding codon to a Stop codon is known as a ______ mutation.

Accepted Answer

A)  AUG 
B)  sense 
C)  release factors 
D)  noninitiator 
E)  hairpin
F) preproteins
G) genetic code
H) penicillin
I) proproteins
J) proofreading
K) UUA
L) synonyms
M) nucleotide cypher
N) streptomycin
O) nonsense
P) revising
Q) cloverleaf 
A)  AUG 
B)  sense 
C)  release factors 
D)  noninitiator 
E)  hairpin
F) preproteins
G) genetic code
H) penicillin
I) proproteins
J) proofreading
K) UUA
L) synonyms
M) nucleotide cypher
N) streptomycin
O) nonsense
P) revising
Q) cloverleaf O

Question 4

Matching
Choose the correct answer from the list.Not all the answers will be used.

-At low concentrations the antibiotic ______ causes misreading of the mRNA.

Accepted Answer

A)  AUG 
B)  sense 
C)  release factors 
D)  noninitiator 
E)  hairpin
F) preproteins
G) genetic code
H) penicillin
I) proproteins
J) proofreading
K) UUA
L) synonyms
M) nucleotide cypher
N) streptomycin
O) nonsense
P) revising
Q) cloverleaf 
A)  AUG 
B)  sense 
C)  release factors 
D)  noninitiator 
E)  hairpin
F) preproteins
G) genetic code
H) penicillin
I) proproteins
J) proofreading
K) UUA
L) synonyms
M) nucleotide cypher
N) streptomycin
O) nonsense
P) revising
Q) cloverleaf

Question 5

Structural studies of the bacterial ribosome indicate which of the following important points regarding function?

Accepted Answer

A) The domains of the 30S subunit appear flexible during protein synthesis. 
B) The large subunit of the ribosome appears to undergo domain motion during protein synthesis. 
C) The small and large subunits of the ribosome appear static throughout protein synthesis. 
D) all of the above 
E) none of the above 
A) The domains of the 30S subunit appear flexible during protein synthesis. 
B) The large subunit of the ribosome appears to undergo domain motion during protein synthesis. 
C) The small and large subunits of the ribosome appear static throughout protein synthesis. 
D) all of the above 
E) none of the above

Question 6

During translation,the reaction catalyzed by peptidyl transferase is coupled to which of the following?

Accepted Answer

A) ATP → ADP + Pi 
B) ATP → AMP + PPi 
C) GTP → GDP + Pi 
D) GTP → GMP + PPi 
E) Release of the tRNA in the P site 
A) ATP → ADP + Pi 
B) ATP → AMP + PPi 
C) GTP → GDP + Pi 
D) GTP → GMP + PPi 
E) Release of the tRNA in the P site

Question 7

Which of the following is TRUE regarding the Shine-Dalgarno sequence?

Accepted Answer

A) It functions as a promoter sequence which recognizes and bonds the sigma factor. 
B) It is part of the operator sequence used to control translation. 
C) It is a nucleotide sequence involved in initiation of translation. 
D) It is a nucleotide sequence involved in termination of translation. 
E) none of the above 
A) It functions as a promoter sequence which recognizes and bonds the sigma factor. 
B) It is part of the operator sequence used to control translation. 
C) It is a nucleotide sequence involved in initiation of translation. 
D) It is a nucleotide sequence involved in termination of translation. 
E) none of the above

Question 8

The Shine-Dalgarno sequence is

Accepted Answer

A) used to align ribosome subunits and initiation translation. 
B) functions as a stop codon. 
C) is used to align RNA polymerase. 
D) is used during transcription termination. 
E) all of the above 
A) used to align ribosome subunits and initiation translation. 
B) functions as a stop codon. 
C) is used to align RNA polymerase. 
D) is used during transcription termination. 
E) all of the above

Question 9

Posttranslational modifications to proteins include all of the following,except

Accepted Answer

A) glycosylation. 
B) phosphorylation. 
C) amino acid derivatization. 
D) peptide joining. 
E) proteolysis. 
A) glycosylation. 
B) phosphorylation. 
C) amino acid derivatization. 
D) peptide joining. 
E) proteolysis.

Question 10

Matching
Choose the correct answer from the list.Not all the answers will be used.

-The ______ is composed of three-nucleotide codons that do not overlap and are read sequentially by the protein-synthesizing machinery.

Accepted Answer

A)  AUG 
B)  sense 
C)  release factors 
D)  noninitiator 
E)  hairpin
F) preproteins
G) genetic code
H) penicillin
I) proproteins
J) proofreading
K) UUA
L) synonyms
M) nucleotide cypher
N) streptomycin
O) nonsense
P) revising
Q) cloverleaf 
A)  AUG 
B)  sense 
C)  release factors 
D)  noninitiator 
E)  hairpin
F) preproteins
G) genetic code
H) penicillin
I) proproteins
J) proofreading
K) UUA
L) synonyms
M) nucleotide cypher
N) streptomycin
O) nonsense
P) revising
Q) cloverleaf

Question 11

Matching
Choose the correct answer from the list.Not all the answers will be used.

-Almost all known tRNAs can be arranged in the so-called ______ secondary structure.

Accepted Answer

A)  AUG 
B)  sense 
C)  release factors 
D)  noninitiator 
E)  hairpin
F) preproteins
G) genetic code
H) penicillin
I) proproteins
J) proofreading
K) UUA
L) synonyms
M) nucleotide cypher
N) streptomycin
O) nonsense
P) revising
Q) cloverleaf 
A)  AUG 
B)  sense 
C)  release factors 
D)  noninitiator 
E)  hairpin
F) preproteins
G) genetic code
H) penicillin
I) proproteins
J) proofreading
K) UUA
L) synonyms
M) nucleotide cypher
N) streptomycin
O) nonsense
P) revising
Q) cloverleaf

Question 12

The thermodynamic requirement for proofreading is met by

Accepted Answer

A) aminoacyl-tRNA binding to the ribosomal A site. 
B) hydrolysis of GTP by EF-Tu 
C) transpeptidation mediated by IF-2. 
D) transpeptidation mediated by RF-3 
E) none of the above. 
A) aminoacyl-tRNA binding to the ribosomal A site. 
B) hydrolysis of GTP by EF-Tu 
C) transpeptidation mediated by IF-2. 
D) transpeptidation mediated by RF-3 
E) none of the above.

Question 13

Matching
Choose the correct answer from the list.Not all the answers will be used.

-Codons that specify the same amino acid are called ______..

Accepted Answer

A)  AUG 
B)  sense 
C)  release factors 
D)  noninitiator 
E)  hairpin
F) preproteins
G) genetic code
H) penicillin
I) proproteins
J) proofreading
K) UUA
L) synonyms
M) nucleotide cypher
N) streptomycin
O) nonsense
P) revising
Q) cloverleaf 
A)  AUG 
B)  sense 
C)  release factors 
D)  noninitiator 
E)  hairpin
F) preproteins
G) genetic code
H) penicillin
I) proproteins
J) proofreading
K) UUA
L) synonyms
M) nucleotide cypher
N) streptomycin
O) nonsense
P) revising
Q) cloverleaf

Question 14

Which of the following is NOT a feature of tRNA structure?

Accepted Answer

A) acceptor or amino acid stem 
B) D arm 
C) anticodon loop 
D) 3' terminal phosphate arm 
E) variable arm 
A) acceptor or amino acid stem 
B) D arm 
C) anticodon loop 
D) 3' terminal phosphate arm 
E) variable arm

Question 15

Which of the following is a ribonucleoprotein required for the delivery of membrane and secretory proteins to the endoplasmic reticulum?

Accepted Answer

A) protein-conducting channel (PC
C)  
B) small ubiquitin-related modifier (SUMO) 
C) trigger factor 
D) calnexin 
E) signal recognition particles (SRP) 
A) protein-conducting channel (PC
C)  
B) small ubiquitin-related modifier (SUMO) 
C) trigger factor 
D) calnexin 
E) signal recognition particles (SRP)

Question 16

Polypeptide synthesis

Accepted Answer

A) proceeds from the C-terminus to the N-terminus. 
B) proceeds from the N-terminus to the C-terminus. 
C) proceeds in both directions simultaneously. 
D) proceeds in either direction once initiated. 
E) proceeds randomly. 
A) proceeds from the C-terminus to the N-terminus. 
B) proceeds from the N-terminus to the C-terminus. 
C) proceeds in both directions simultaneously. 
D) proceeds in either direction once initiated. 
E) proceeds randomly.

Question 17

In E.coli,base-pairing between an mRNA's ______ and the 3' end of the 16S rRNA permits the ribosome to select the proper initiation codon,thus minimizing ______.

Accepted Answer

A) start codon;abortive initiation 
B) Shine-Dalgarno sequence;abortive initiation 
C) start codon;frameshift mutations 
D) Shine-Dalgarno sequence;frameshift mutations 
E) none of the above 
A) start codon;abortive initiation 
B) Shine-Dalgarno sequence;abortive initiation 
C) start codon;frameshift mutations 
D) Shine-Dalgarno sequence;frameshift mutations 
E) none of the above

Question 18

The site on the ribosome complex which binds the new incoming amino acid- tRNA is called the

Accepted Answer

A) P site. 
B) A site. 
C) E site. 
D) 50 S site. 
E) 30 S site. 
A) P site. 
B) A site. 
C) E site. 
D) 50 S site. 
E) 30 S site.

Question 19

Based on the structure shown below,which of the following correctly represents the sequence that would be present at the "XYZ" position?

Accepted Answer

A) UGG 
B) TGG 
C) ACC 
D) Cannot be determined from the given data. 
E) None of the above is the correct sequence. 
A) UGG 
B) TGG 
C) ACC 
D) Cannot be determined from the given data. 
E) None of the above is the correct sequence.

Question 20

Considering elongation of peptides via ribosome-mediated peptide synthesis,how many ATP equivalents are required for addition of on amino acid to the growing peptide chain and translocation such that the assembly is prepared for the subsequent addition of another amino acid?

Accepted Answer

A) 0 
B) 1 
C) 2 
D) 3 
E) 4 
A) 0 
B) 1 
C) 2 
D) 3 
E) 4

Exam 27: Protein Synthesis

Which of the following best describes the method used for error minimization or proofreading to ensure the correct charging of the tRNAs?

During translation,translocation of the ribosome is driven by which of the following?

Matching Choose the correct answer from the list.Not all the answers will be used. -A mutation that converts an aminoacyl-coding codon to a Stop codon is known as a ______ mutation.

Matching Choose the correct answer from the list.Not all the answers will be used. -At low concentrations the antibiotic ______ causes misreading of the mRNA.

Structural studies of the bacterial ribosome indicate which of the following important points regarding function?

During translation,the reaction catalyzed by peptidyl transferase is coupled to which of the following?

Which of the following is TRUE regarding the Shine-Dalgarno sequence?

The Shine-Dalgarno sequence is

Posttranslational modifications to proteins include all of the following,except

Matching Choose the correct answer from the list.Not all the answers will be used. -The ______ is composed of three-nucleotide codons that do not overlap and are read sequentially by the protein-synthesizing machinery.

Matching Choose the correct answer from the list.Not all the answers will be used. -Almost all known tRNAs can be arranged in the so-called ______ secondary structure.

The thermodynamic requirement for proofreading is met by

Matching Choose the correct answer from the list.Not all the answers will be used. -Codons that specify the same amino acid are called ______..

Which of the following is NOT a feature of tRNA structure?

Which of the following is a ribonucleoprotein required for the delivery of membrane and secretory proteins to the endoplasmic reticulum?

Polypeptide synthesis

In E.coli,base-pairing between an mRNA's ______ and the 3' end of the 16S rRNA permits the ribosome to select the proper initiation codon,thus minimizing ______.

The site on the ribosome complex which binds the new incoming amino acid- tRNA is called the

Based on the structure shown below,which of the following correctly represents the sequence that would be present at the "XYZ" position?

Considering elongation of peptides via ribosome-mediated peptide synthesis,how many ATP equivalents are required for addition of on amino acid to the growing peptide chain and translocation such that the assembly is prepared for the subsequent addition of another amino acid?

Introduction to the Chemistry of Life

Water

Nucleotides, nucleic Acids, and Genetic Information

Amino Acids

Proteins: Primary Structure

Proteins: Three-Dimensional Structure

Protein Function Part I: Myoglobin and Hemoglobin

Carbohydrates

Lipids and Biological Membranes

Membrane Transport

Enzyme Catalysis

Enzyme Kinetics, inhibition and Control

Biochemical Signaling

Introduction to Metabolism

Glucose Catabolism

Glycogen Metabolism and Gluconeogenesis

Citric Acid Cycle

Electron Transport and Oxidative Phosphorylation

Photosynthesis

Lipid Metabolism

Amino Acid Metabolism

Mammalian Fuel Metabolism: Integration and Regulation

Nucleotide Metabolism

Nucleic Acid Structure

DNA Replication, repair and Recombination

Transcription and Rna Processing

Regulation of Gene Expression

Filters

In E.coli,base-pairing between an mRNA's and the 3' end of the 16S rRNA permits the ribosome to select the proper initiation codon,thus minimizing .