Question 1

Which of the following is NOT a component required for peptide chain initiation?

Accepted Answer

A) DNA 
B) 30S and 50S ribosomal subunits 
C) initiation factors 
D) GTP and f-Met-tRNAifMet 
A) DNA 
B) 30S and 50S ribosomal subunits 
C) initiation factors 
D) GTP and f-Met-tRNAifMet

Question 2

The Shine-Dalgarno sequence found in prokaryotic systems resides on the 5'-end of mRNA.What function does the site serve?

Accepted Answer

A) It is for formylmethionine binding. 
B) It is for polymerase binding. 
C) It is for initiation factor binding. 
D) It is for ribosome binding. 
A) It is for formylmethionine binding. 
B) It is for polymerase binding. 
C) It is for initiation factor binding. 
D) It is for ribosome binding.

Question 3

What is the linkage between the amino acid and the tRNA in an amino-acyl tRNA complex?

Accepted Answer

A) an aminoacyl ester 
B) an amide 
C) an acid anhydride 
D) a diester 
A) an aminoacyl ester 
B) an amide 
C) an acid anhydride 
D) a diester

Question 4

What is the minimum number of high-energy phosphoric anhydride bonds per amino acid required as energy expenditure for protein synthesis?

Accepted Answer

A) 0 
B) 2 
C) 4 
D) 6 
A) 0 
B) 2 
C) 4 
D) 6

Question 5

What is the ribosomal peptidyl transferase transformed into by the termination signal complex?

Accepted Answer

A) a lyase 
B) an isomerase 
C) a hydrolase 
D) a transferase 
A) a lyase 
B) an isomerase 
C) a hydrolase 
D) a transferase

Question 6

By what factor is protein synthesis faster in prokaryotic cells than in eukaryotic cells?

Accepted Answer

A) 2 
B) 10 
C) 30 
D) 40 
A) 2 
B) 10 
C) 30 
D) 40

Question 7

Which of the following is NOT a characteristic of the "wobble position"?

Accepted Answer

A) It is the first base of the codon. 
B) A certain amount of play might occur in base pairing at this position. 
C) The first-base anticodon U could recognize either an A or G in the wobble position. 
D) The first-base anticodon G could recognize either a U or C in the wobble position. 
A) It is the first base of the codon. 
B) A certain amount of play might occur in base pairing at this position. 
C) The first-base anticodon U could recognize either an A or G in the wobble position. 
D) The first-base anticodon G could recognize either a U or C in the wobble position.

Question 8

Which of the following is NOT a characteristic of ribosomal subunit assembly under appropriate conditions of pH and ionic strength?

Accepted Answer

A) Ribosomes assembly is energy dependent and not spontaneous. 
B) No intervention by any additional factors or chaperones is required. 
C) Ribosomal proteins bind in a specific order. 
D) rRNA acts as a scaffold upon which various ribosomal proteins convene. 
A) Ribosomes assembly is energy dependent and not spontaneous. 
B) No intervention by any additional factors or chaperones is required. 
C) Ribosomal proteins bind in a specific order. 
D) rRNA acts as a scaffold upon which various ribosomal proteins convene.

Question 9

Which of these cellular components are the agents of protein synthesis?

Accepted Answer

A) nuclei 
B) mitochondria 
C) chloroplasts 
D) ribosomes 
A) nuclei 
B) mitochondria 
C) chloroplasts 
D) ribosomes

Question 10

Which of these steps is required for termination of translation in prokaryotic cells?

Accepted Answer

A) displacement of EF-G by EF-Tu:aminoacyl-tRNA 
B) ternary interaction of the release factor and the termination tRNA with the termination codon 
C) interaction of release factors with the termination codon 
D) release factor interaction with the Shine-Dalgarno sequence and subsequent dissociation of the 2 ribosomal subunits 
A) displacement of EF-G by EF-Tu:aminoacyl-tRNA 
B) ternary interaction of the release factor and the termination tRNA with the termination codon 
C) interaction of release factors with the termination codon 
D) release factor interaction with the Shine-Dalgarno sequence and subsequent dissociation of the 2 ribosomal subunits

Question 11

Which of the following is NOT a feature of the tRNA molecule with the anticodon 5'CAU?

Accepted Answer

A) It is the anticodon for tRNAfmet. 
B) The wobble base in the anticodon would be cytosine. 
C) Its anticodon can theoretically base pair with up to 3 different codons. 
D) Its anticodon can base pair to the codon 5'AUG. 
A) It is the anticodon for tRNAfmet. 
B) The wobble base in the anticodon would be cytosine. 
C) Its anticodon can theoretically base pair with up to 3 different codons. 
D) Its anticodon can base pair to the codon 5'AUG.

Question 12

The anticodon of a tRNA is 5'UUG.What codon(s)can be recognized,theoretically,by this tRNA?

Accepted Answer

A) 5'CAA only 
B) 5'CAA & 5'CAG 
C) 5'AAC only 
D) 5'AAC & 5' GAC 
A) 5'CAA only 
B) 5'CAA & 5'CAG 
C) 5'AAC only 
D) 5'AAC & 5' GAC

Question 13

Codons representing the same amino acid or chemically similar amino acids tend to be similar in sequence,often differing only in the third base.What is this feature called?

Accepted Answer

A) home-base degeneracy 
B) first-base similarity 
C) second-base type similarity 
D) third-base degeneracy 
A) home-base degeneracy 
B) first-base similarity 
C) second-base type similarity 
D) third-base degeneracy

Question 14

Which of the following is NOT a difference between prokaryotic and eukaryotic protein synthesis?

Accepted Answer

A) Prokaryote protein synthesis is initiated by f-Met,while eukaryotic is initiated by Met. 
B) Prokaryotes use a 30S small ribosomal subunit,while eukaryotes use a 40S small ribosomal subunit. 
C) Prokaryotic and eukaryotic translation initiations differ significantly in mechanism and process. 
D) Prokaryotic termination involves 1 release factor,while eukaryotic termination involves 3. 
A) Prokaryote protein synthesis is initiated by f-Met,while eukaryotic is initiated by Met. 
B) Prokaryotes use a 30S small ribosomal subunit,while eukaryotes use a 40S small ribosomal subunit. 
C) Prokaryotic and eukaryotic translation initiations differ significantly in mechanism and process. 
D) Prokaryotic termination involves 1 release factor,while eukaryotic termination involves 3.

Question 15

Which of the following is NOT a dominant mechanism for control of eukaryotic peptide chain initiation?

Accepted Answer

A) allosteric regulation 
B) cofactor availability control 
C) phosphorylation/dephosphorylation 
D) competitive inhibition 
A) allosteric regulation 
B) cofactor availability control 
C) phosphorylation/dephosphorylation 
D) competitive inhibition

Question 16

What is the term for all members of a set of tRNAs specific for a particular amino acid?

Accepted Answer

A) companion 
B) tRNA family 
C) isoacid 
D) isoacceptor 
A) companion 
B) tRNA family 
C) isoacid 
D) isoacceptor

Question 17

Which of the following recognizes "stop" or nonsense codons through specific tripeptide sequences that serve as an equivalent of the tRNA anticodon loop?

Accepted Answer

A) tRNA 
B) nucleotides 
C) rRNA 
D) release factors 
A) tRNA 
B) nucleotides 
C) rRNA 
D) release factors

Question 18

Which of these actions converts the language of genetic information embodied in the base sequence of a mRNA molecule into the amino acid sequence of a polypeptide chain?

Accepted Answer

A) translocation 
B) translation 
C) transcription 
D) degradation 
A) translocation 
B) translation 
C) transcription 
D) degradation

Question 19

The actual peptide bond-forming step in translation is referred to as peptidyl transfer.Which enzyme catalyzes this process?

Accepted Answer

A) peptidase 
B) transpeptidase 
C) peptidyl transferase 
D) translocase 
A) peptidase 
B) transpeptidase 
C) peptidyl transferase 
D) translocase

Question 20

What is the function of elongation factor Tu (EF-Tu)?

Accepted Answer

A) to bind GTP promoting translocation of ribosomes along mRNA 
B) to bind to 30S subunit and drive mRNA binding 
C) to bind aminoacyl-tRNA in the presence of GTP 
D) to bind initiator tRNA and GTP 
A) to bind GTP promoting translocation of ribosomes along mRNA 
B) to bind to 30S subunit and drive mRNA binding 
C) to bind aminoacyl-tRNA in the presence of GTP 
D) to bind initiator tRNA and GTP

Exam 30: Protein Synthesis

Which of the following is NOT a component required for peptide chain initiation?

The Shine-Dalgarno sequence found in prokaryotic systems resides on the 5'-end of mRNA.What function does the site serve?

What is the linkage between the amino acid and the tRNA in an amino-acyl tRNA complex?

What is the minimum number of high-energy phosphoric anhydride bonds per amino acid required as energy expenditure for protein synthesis?

What is the ribosomal peptidyl transferase transformed into by the termination signal complex?

By what factor is protein synthesis faster in prokaryotic cells than in eukaryotic cells?

Which of the following is NOT a characteristic of the "wobble position"?

Which of the following is NOT a characteristic of ribosomal subunit assembly under appropriate conditions of pH and ionic strength?

Which of these cellular components are the agents of protein synthesis?

Which of these steps is required for termination of translation in prokaryotic cells?

Which of the following is NOT a feature of the tRNA molecule with the anticodon 5'CAU?

The anticodon of a tRNA is 5'UUG.What codon(s)can be recognized,theoretically,by this tRNA?

Codons representing the same amino acid or chemically similar amino acids tend to be similar in sequence,often differing only in the third base.What is this feature called?

Which of the following is NOT a difference between prokaryotic and eukaryotic protein synthesis?

Which of the following is NOT a dominant mechanism for control of eukaryotic peptide chain initiation?

What is the term for all members of a set of tRNAs specific for a particular amino acid?

Which of the following recognizes "stop" or nonsense codons through specific tripeptide sequences that serve as an equivalent of the tRNA anticodon loop?

Which of these actions converts the language of genetic information embodied in the base sequence of a mRNA molecule into the amino acid sequence of a polypeptide chain?

The actual peptide bond-forming step in translation is referred to as peptidyl transfer.Which enzyme catalyzes this process?

What is the function of elongation factor Tu (EF-Tu)?

The Facts of Life: Chemistry Is the Logic of Biological Phenomena

Water: the Medium of Life

Thermodynamics of Biological Systems

Amino Acids

Proteins: Their Primary Structure and Biological Functions

Proteins: Secondary, tertiary, and Quaternary Structure

Carbohydrates and the Glycoconjugates of Cell Surfaces

Lipids

Lipid Biosynthesis

Membranes and Membrane Transport

The Reception and Transmission of Extracellular Information

Enzymes Kinetics and Specificity

Mechanisms of Enzyme Action

Enzyme Regulation

Molecular Motors

Nutrition and the Organization of Metabolism

Glycolysis

The Tricarboxylic Acid Cycle

Electron Transport and Oxidative Phosphorylation

Photosynthesis

Gluconeogenesis, glycogen Metabolism, and the Pentose Phosphate Pathway

Fatty Acid Catabolism

Nitrogen Acquisition and Amino Acid Metabolism

Nucleotides and Nucleic Acids

Structure of Nucleic Acids

Synthesis and Degradation of Nucleotides

Recombinant Dna: Cloning and Creation of Chimeric Genes

DNA Metabolism: Replication, recombination, and Repair

Transcription and the Regulation of Gene Expression

Post-Transcriptional Regulation of Gene Expression

Completing the Protein Life Cycle: Folding, processing, and Degradation

Metabolic Integration and Organ Specialization

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