Question 1

In bacteria, translation of the mRNA begins

Accepted Answer

A)  during the synthesis of the mRNA. 
B)  after synthesis of the mRNA has been completed. 
C)  after 5' capping of the mRNA. 
D)  after all processing (capping, polyadenylation, and removal of introns) has taken place. 
A)  during the synthesis of the mRNA. 
B)  after synthesis of the mRNA has been completed. 
C)  after 5' capping of the mRNA. 
D)  after all processing (capping, polyadenylation, and removal of introns) has taken place.

Question 2

Exceptions to the universality of the genetic code have been observed in

Accepted Answer

A)  viruses 
B)  prokaryotes 
C)  eukaryotes 
D)  mitochondria and 16 other organisms, including some algae and fungae 
A)  viruses 
B)  prokaryotes 
C)  eukaryotes 
D)  mitochondria and 16 other organisms, including some algae and fungae

Question 3

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

Accepted Answer

A)  Keep the ribosomal subunits bound together. 
B)  Lead the incoming tRNA to its correct position on the ribosome. 
C)  Carry GTP to provide energy for certain steps in the elongation process. 
D)  Regenerate the elongation factors by replacing GTP for GDP. 
E)  The elongation factors do all of these. 
A)  Keep the ribosomal subunits bound together. 
B)  Lead the incoming tRNA to its correct position on the ribosome. 
C)  Carry GTP to provide energy for certain steps in the elongation process. 
D)  Regenerate the elongation factors by replacing GTP for GDP. 
E)  The elongation factors do all of these.

Question 4

​ Identify an amino acid that is coded by only one codon.

Accepted Answer

A)  Methionine 
B)  Leucine 
C)  Arginine 
D)  Histidine 
A)  Methionine 
B)  Leucine 
C)  Arginine 
D)  Histidine

Question 5

The tRNAs may bind to the standard stop codons

Accepted Answer

A)  in cellular organelles which use a modified genetic code. 
B)  to accommodate the tRNA for the unusual amino acid selenocysteine. 
C)  when the anticodon in a tRNA mutates to a sequence which can bind. 
D)  All of these 
A)  in cellular organelles which use a modified genetic code. 
B)  to accommodate the tRNA for the unusual amino acid selenocysteine. 
C)  when the anticodon in a tRNA mutates to a sequence which can bind. 
D)  All of these

Question 6

The activating enzymes can actually remove wrong amino acids attached to a tRNA.

Accepted Answer

A) True 
 B)False

Question 7

The genetic code is said to be degenerate. This means that

Accepted Answer

A)  each codon codes for more than one amino acid. 
B)  each anticodon can interact with many different triplet sequences in the mRNA, which may differ in any or all of the three nucleotides. 
C)  many of the amino acids are coded for by different codons. 
D)  the code is universally used by virtually all species. 
A)  each codon codes for more than one amino acid. 
B)  each anticodon can interact with many different triplet sequences in the mRNA, which may differ in any or all of the three nucleotides. 
C)  many of the amino acids are coded for by different codons. 
D)  the code is universally used by virtually all species.

Question 8

What type of assay using tRNAs and ribosomes enabled complete determination of the genetic code?

Accepted Answer

A)  filter binding assays 
B)  high performance chromatography 
C)  electrophoresis 
D)  density gradient centrifugation 
A)  filter binding assays 
B)  high performance chromatography 
C)  electrophoresis 
D)  density gradient centrifugation

Question 9

​ Identify the component required for the chain initiation step of protein synthesis.

Accepted Answer

A)  DNA helicase 
B)  Release factors 
C)  30S ribosomal subunit 
D)  UAA 
A)  DNA helicase 
B)  Release factors 
C)  30S ribosomal subunit 
D)  UAA

Question 10

Which of the following is not true?

Accepted Answer

A)  A single activating enzyme can interact with all the tRNAs for its corresponding amino acid 
B)  The selectivity of the aminoacyl-tRNA synthetases for their tRNA molecules is often called the second genetic code 
C)  There are two major classes of aminoacyl-tRNA synthetases 
D)  aminoacyl-tRNA synthetases link amino acids to tRNA molecules without the need for an energy source 
A)  A single activating enzyme can interact with all the tRNAs for its corresponding amino acid 
B)  The selectivity of the aminoacyl-tRNA synthetases for their tRNA molecules is often called the second genetic code 
C)  There are two major classes of aminoacyl-tRNA synthetases 
D)  aminoacyl-tRNA synthetases link amino acids to tRNA molecules without the need for an energy source

Question 11

Which of the following statements concerning tRNAs is false ?

Accepted Answer

A)  They have distinctive cloverleaf tertiary structures 
B)  They are unique in that they are transcribed by DNA polymerases 
C)  They contain many modified nucleobases 
D)  They contain the anticodon sequence 
A)  They have distinctive cloverleaf tertiary structures 
B)  They are unique in that they are transcribed by DNA polymerases 
C)  They contain many modified nucleobases 
D)  They contain the anticodon sequence

Question 12

Which antibiotic confirmed that the growing peptide chain is transferred to the amino group of the incoming tRNA?

Accepted Answer

A)  Puromycin 
B)  Streptomycin 
C)  Cyclohexamide 
D)  None of these antibiotics was useful for studying the mechanism of protein synthesis. 
E)  None of these antibiotics actually interferes with peptide transfer. 
A)  Puromycin 
B)  Streptomycin 
C)  Cyclohexamide 
D)  None of these antibiotics was useful for studying the mechanism of protein synthesis. 
E)  None of these antibiotics actually interferes with peptide transfer.

Question 13

The initial step in the formation of an aminoacyl-tRNA is

Accepted Answer

A)  esterification of the tRNA 
B)  activation of the amino acid by reaction with ATP 
C)  activation of the tRNA by reaction with ATP 
D)  interaction of the mRNA with the tRNA 
A)  esterification of the tRNA 
B)  activation of the amino acid by reaction with ATP 
C)  activation of the tRNA by reaction with ATP 
D)  interaction of the mRNA with the tRNA

Question 14

An aminoacyl-adenylate contains

Accepted Answer

A)  an ester bond 
B)  an acid anhydride bond 
C)  an amide bond 
D)  an ether bond 
A)  an ester bond 
B)  an acid anhydride bond 
C)  an amide bond 
D)  an ether bond

Question 15

Which of the following is true concerning protein synthesis and memory?

Accepted Answer

A)  Animals that cannot make new proteins have no memories 
B)  Inhibition of protein synthesis in eukaryotes leads to lack of long term memory 
C)  Production of CREB is inhibited when strong memories are made 
D)  none of these is true 
A)  Animals that cannot make new proteins have no memories 
B)  Inhibition of protein synthesis in eukaryotes leads to lack of long term memory 
C)  Production of CREB is inhibited when strong memories are made 
D)  none of these is true

Question 16

There is no codon for the amino acid hydroxyproline, but this amino acid is a prominent feature of collagen structure. Which of the following is a likely explanation?

Accepted Answer

A)  Hydroxyproline is substituted for proline after translation by a cut and patch mechanism. 
B)  Proline is covalently modified to give hydroxyproline after translation. 
C)  There is an alternative mechanism for synthesis of proteins that contain hydroxyproline. 
D)  It is not possible to form a hypothesis from the information given. 
A)  Hydroxyproline is substituted for proline after translation by a cut and patch mechanism. 
B)  Proline is covalently modified to give hydroxyproline after translation. 
C)  There is an alternative mechanism for synthesis of proteins that contain hydroxyproline. 
D)  It is not possible to form a hypothesis from the information given.

Question 17

​ In the process of translation, before an amino acid can be incorporated into a growing protein chain, the activation process of the amino acid involves _____.

Accepted Answer

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

Question 18

Which of the following is not a prokaryotic elongation factor?

Accepted Answer

A)  EF-Tu 
B)  EF-Ts 
C)  EF-G 
D)  EF-P 
E)  all of these are prokaryotic elognation factors 
A)  EF-Tu 
B)  EF-Ts 
C)  EF-G 
D)  EF-P 
E)  all of these are prokaryotic elognation factors

Question 19

As in RNA and DNA synthesis, the synthesis of proteins follows the following steps, except :

Accepted Answer

A)  Activation of monomers 
B)  Initiation 
C)  Elongation 
D)  Termination 
E)  All of these are involved in all polymer synthesis 
A)  Activation of monomers 
B)  Initiation 
C)  Elongation 
D)  Termination 
E)  All of these are involved in all polymer synthesis

Question 20

Which of the following is associated with post-translational processing of proteins?

Accepted Answer

A)  Folding into the 3-dimensional shape 
B)  Breaking large proteins into several components with differing functions 
C)  Forming disulfide bonds 
D)  Modification of specific amino acids 
E)  All of these 
A)  Folding into the 3-dimensional shape 
B)  Breaking large proteins into several components with differing functions 
C)  Forming disulfide bonds 
D)  Modification of specific amino acids 
E)  All of these

Exam 12: Protein Synthesis Translation of the Genetic Message

In bacteria, translation of the mRNA begins

Exceptions to the universality of the genetic code have been observed in

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

​ Identify an amino acid that is coded by only one codon.

The tRNAs may bind to the standard stop codons

The activating enzymes can actually remove wrong amino acids attached to a tRNA.

The genetic code is said to be degenerate. This means that

What type of assay using tRNAs and ribosomes enabled complete determination of the genetic code?

​ Identify the component required for the chain initiation step of protein synthesis.

Which of the following is not true?

Which of the following statements concerning tRNAs is false ?

Which antibiotic confirmed that the growing peptide chain is transferred to the amino group of the incoming tRNA?

The initial step in the formation of an aminoacyl-tRNA is

An aminoacyl-adenylate contains

Which of the following is true concerning protein synthesis and memory?

There is no codon for the amino acid hydroxyproline, but this amino acid is a prominent feature of collagen structure. Which of the following is a likely explanation?

​ In the process of translation, before an amino acid can be incorporated into a growing protein chain, the activation process of the amino acid involves _____.

Which of the following is not a prokaryotic elongation factor?

As in RNA and DNA synthesis, the synthesis of proteins follows the following steps, except :

Which of the following is associated with post-translational processing of proteins?

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

Identify an amino acid that is coded by only one codon.

Identify the component required for the chain initiation step of protein synthesis.

In the process of translation, before an amino acid can be incorporated into a growing protein chain, the activation process of the amino acid involves _____.