Question 1

​ tRNAmet and tRNAfmet contain a sequence _____ that pairs with the sequence 5'-AUG-3' in the mRNA sequence .

Accepted Answer

A)  5'-UAC-3' 
B)  3'-UAC-5' 
C)  5'-CAU-3' 
D)  3'-CAU-5' 
A)  5'-UAC-3' 
B)  3'-UAC-5' 
C)  5'-CAU-3' 
D)  3'-CAU-5' B

Question 2

It was recently discovered that AUG is not always the start codon in which of the following systems?

Accepted Answer

A)  viruses 
B)  mammalian immune system proteins 
C)  mitochondria 
D)  all of these 
A)  viruses 
B)  mammalian immune system proteins 
C)  mitochondria 
D)  all of these B

Question 3

An aminoacyl-tRNA is initially bound to the ribosome

Accepted Answer

A)  at the A site on the 50S subunit 
B)  at the P site on the 50S subunit 
C)  at the A site on the 30S subunit 
D)  at the P site on the 30S subunit 
A)  at the A site on the 50S subunit 
B)  at the P site on the 50S subunit 
C)  at the A site on the 30S subunit 
D)  at the P site on the 30S subunit A

Question 4

The initiation of eukaryotic translation can be a control point in overall gene expression?

Accepted Answer

A) True 
 B)False

Question 5

The mRNA must contain the following to allow for initiation of protein synthesis in E. coli .

Accepted Answer

A)  A purine rich sequence to bind to the ribosome. 
B)  A pyrimidine rich sequence to bind to the ribosome. 
C)  A Shine-Delgarno sequence. 
D)  A purine rich sequence to bind to the ribosome and a Shine-Delgarno sequence. 
E)  A pyrimidine rich sequence to bind to the ribosome and a Shine-Delgarno sequence. 
A)  A purine rich sequence to bind to the ribosome. 
B)  A pyrimidine rich sequence to bind to the ribosome. 
C)  A Shine-Delgarno sequence. 
D)  A purine rich sequence to bind to the ribosome and a Shine-Delgarno sequence. 
E)  A pyrimidine rich sequence to bind to the ribosome and a Shine-Delgarno sequence.

Question 6

The actual functions of the factors in eukaryotes are similar to the functions of these factors in bacteria.

Accepted Answer

A) True 
 B)False

Question 7

Which linkage best describes the covalent bond between an amino acid (AA) and its tRNA?

Accepted Answer

A)  Amino group of AA linked to 5' − OH of tRNA. 
B)  Amino group of AA linked to 5' phosphate of tRNA. 
C)  Carboxyl group of AA linked to 3' − OH of tRNA. 
D)  Carboxyl group of AA linked to 3' phosphate of tRNA. 
A)  Amino group of AA linked to 5' − OH of tRNA. 
B)  Amino group of AA linked to 5' phosphate of tRNA. 
C)  Carboxyl group of AA linked to 3' − OH of tRNA. 
D)  Carboxyl group of AA linked to 3' phosphate of tRNA.

Question 8

The first tRNA (bearing fmet) binds to the

Accepted Answer

A)  "A" site of the ribosome. 
B)  "P" site on the ribosome. 
C)  "E" site on the ribosome. 
A)  "A" site of the ribosome. 
B)  "P" site on the ribosome. 
C)  "E" site on the ribosome.

Question 9

Which of the following is necessary for chain termination in protein synthesis?

Accepted Answer

A)  termination codons of mRNA 
B)  release factors 
C)  GTP 
D)  all of these 
E)  none of these 
A)  termination codons of mRNA 
B)  release factors 
C)  GTP 
D)  all of these 
E)  none of these

Question 10

Transfer RNAs contain an anti-codon loop meant to match (base pair) with a codon on an mRNA.

Accepted Answer

A) True 
 B)False

Question 11

What is the maximum number of amino acids that can be specified by a codon consisting of a sequence of two bases?

Accepted Answer

A)  4 
B)  8 
C)  16 
D)  20 
A)  4 
B)  8 
C)  16 
D)  20

Question 12

Wobble allows a single codon to code for more than one amino acid.

Accepted Answer

A) True 
 B)False

Question 13

What is the mode of action of puromycin in the inhibition of protein synthesis?

Accepted Answer

A)  inhibition of peptidyl transferase 
B)  inactivation of EF − G 
C)  termination of the growing polypeptide chain 
D)  dissociation of mRNA from the ribosome 
A)  inhibition of peptidyl transferase 
B)  inactivation of EF − G 
C)  termination of the growing polypeptide chain 
D)  dissociation of mRNA from the ribosome

Question 14

Which of the following is not an advantage of degeneracy in the genetic code?

Accepted Answer

A)  More than one amino acid can bind to a tRNA. 
B)  Each tRNA can bind to more than one codon. 
C)  Most codons can bind to more than one tRNA. 
D)  Fewer tRNA molecules are needed. 
A)  More than one amino acid can bind to a tRNA. 
B)  Each tRNA can bind to more than one codon. 
C)  Most codons can bind to more than one tRNA. 
D)  Fewer tRNA molecules are needed.

Question 15

Which of the following is not a function of initiation factors in E. coli ?

Accepted Answer

A)  Prevent the ribosomal subunits from binding together. 
B)  Lead the initial tRNA to its correct position on the large subunit of the ribosome. 
C)  Help the mRNA to bind to the tRNA. 
D)  Carry GTP to provide energy for certain steps in the initiation process. 
E)  The initiation factors do all of these. 
A)  Prevent the ribosomal subunits from binding together. 
B)  Lead the initial tRNA to its correct position on the large subunit of the ribosome. 
C)  Help the mRNA to bind to the tRNA. 
D)  Carry GTP to provide energy for certain steps in the initiation process. 
E)  The initiation factors do all of these.

Question 16

Which category of RNA carries amino acids for the process of translation?

Accepted Answer

A)  mRNA 
B)  rRNA 
C)  snRNA 
D)  tRNA 
A)  mRNA 
B)  rRNA 
C)  snRNA 
D)  tRNA

Question 17

In protein synthesis formation of new peptide bonds is catalyzed by

Accepted Answer

A)  elongation factor EF − Tu 
B)  elongation factor EF − Ts 
C)  elongation factor EF − G 
D)  peptidyl transferase 
A)  elongation factor EF − Tu 
B)  elongation factor EF − Ts 
C)  elongation factor EF − G 
D)  peptidyl transferase

Question 18

Protein synthesis in prokaryotes always starts with

Accepted Answer

A)  a methionine residue 
B)  a formylmethionine residue 
C)  a cysteine residue 
D)  no specific residue 
A)  a methionine residue 
B)  a formylmethionine residue 
C)  a cysteine residue 
D)  no specific residue

Question 19

How do eukaryotic ribosomes prevent false starts at inappropriate parts of the mRNA?

Accepted Answer

A)  There is a consensus sequence, called the Kozak sequence, surrounding the start codon in eukaryotes. 
B)  The Shine-Dalgarno sequence positions the ribosome properly, just as in prokaryotes. 
C)  Only one start codon ever appears in eukaryotic mRNA, so false starts are not a problem. 
D)  Nothing; false starts are quite common in eukaryotic translation. 
A)  There is a consensus sequence, called the Kozak sequence, surrounding the start codon in eukaryotes. 
B)  The Shine-Dalgarno sequence positions the ribosome properly, just as in prokaryotes. 
C)  Only one start codon ever appears in eukaryotic mRNA, so false starts are not a problem. 
D)  Nothing; false starts are quite common in eukaryotic translation.

Question 20

After peptide bond formation takes place, what step is necessary for continuation of protein synthesis?

Accepted Answer

A)  binding of uncharged tRNA to the ribosome 
B)  binding of EF − Tu 
C)  binding of EF − Ts 
D)  translocation of the ribosome 
A)  binding of uncharged tRNA to the ribosome 
B)  binding of EF − Tu 
C)  binding of EF − Ts 
D)  translocation of the ribosome

Exam 12: Protein Synthesis Translation of the Genetic Message

​ tRNAmet and tRNAfmet contain a sequence _____ that pairs with the sequence 5'-AUG-3' in the mRNA sequence .

It was recently discovered that AUG is not always the start codon in which of the following systems?

An aminoacyl-tRNA is initially bound to the ribosome

The initiation of eukaryotic translation can be a control point in overall gene expression?

The mRNA must contain the following to allow for initiation of protein synthesis in E. coli .

The actual functions of the factors in eukaryotes are similar to the functions of these factors in bacteria.

Which linkage best describes the covalent bond between an amino acid (AA) and its tRNA?

The first tRNA (bearing fmet) binds to the

Which of the following is necessary for chain termination in protein synthesis?

Transfer RNAs contain an anti-codon loop meant to match (base pair) with a codon on an mRNA.

What is the maximum number of amino acids that can be specified by a codon consisting of a sequence of two bases?

Wobble allows a single codon to code for more than one amino acid.

What is the mode of action of puromycin in the inhibition of protein synthesis?

Which of the following is not an advantage of degeneracy in the genetic code?

Which of the following is not a function of initiation factors in E. coli ?

Which category of RNA carries amino acids for the process of translation?

In protein synthesis formation of new peptide bonds is catalyzed by

Protein synthesis in prokaryotes always starts with

How do eukaryotic ribosomes prevent false starts at inappropriate parts of the mRNA?

After peptide bond formation takes place, what step is necessary for continuation of protein synthesis?

Biochemistry and the Organization of Cells

Water the Solvent for Biochemical Reactions

Amino Acids and Peptides

The Three Dimensional Structure of Proteins

Protein Purification and Characterization Techniques

The Behavior of Proteins Enzymes

The Behavior of Proteins Enzymes Mechanisms and Control

Lipids and Proteins Are Associated in Biological Membranes

Nucleic Acids How Structure Conveys Information

Biosynthesis of Nucleic Acids Replication

Transcription of the Genetic Code the Biosynthesis of Rna

Nucleic Acid Biotechnology Techniques

Viruses Cancer and Immunology

The Importance of Energy Changes and Electron Transfer in Metabolism

Carbohydrates

Glycolysis

Storage Mechanisms and Control in Carbohydrate Metabolism

The Citric Acid Cycle

Electron Transport and Oxidative Phosphorylation

Lipid Metabolism

Photosynthesis

The Metabolism of Nitrogen

Integration of Metabolism Cellular Signaling

Filters

tRNA^met and tRNA^fmet contain a sequence _____ that pairs with the sequence 5'-AUG-3' in the mRNA sequence .