Question 1

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

Question 2

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 3

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 4

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 5

Wobble allows each codon to interact with more than one tRNA.

Accepted Answer

A) True 
 B)False

Question 6

Activation of amino acids always takes place

Accepted Answer

A)  on the ribosomes 
B)  on a ribosomal subunit 
C)  on the rough endoplasmic reticulum 
D)  in the cytoplasm 
A)  on the ribosomes 
B)  on a ribosomal subunit 
C)  on the rough endoplasmic reticulum 
D)  in the cytoplasm

Question 7

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 8

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 9

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 10

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 11

A polysome is

Accepted Answer

A)  a complex consisting of one mRNA to which several ribosomes are attached 
B)  a polypeptide chain in the process of being formed 
C)  an intermediate stage in the self-assembly of ribosomes 
D)  an aggregate of ribosomal proteins 
A)  a complex consisting of one mRNA to which several ribosomes are attached 
B)  a polypeptide chain in the process of being formed 
C)  an intermediate stage in the self-assembly of ribosomes 
D)  an aggregate of ribosomal proteins

Question 12

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 13

Which of the following statements concerning the genetic code is false?

Accepted Answer

A)  It is based on triplets. 
B)  It is non-overlapping. 
C)  Commas are used. 
D)  It is degenerate. 
A)  It is based on triplets. 
B)  It is non-overlapping. 
C)  Commas are used. 
D)  It is degenerate.

Question 14

Aminoacyl-tRNA Synthetases are involved in which step of translation?

Accepted Answer

A)  activation 
B)  initiation 
C)  elongation 
D)  termination 
E)  none of these 
A)  activation 
B)  initiation 
C)  elongation 
D)  termination 
E)  none of these

Question 15

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 16

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

Accepted Answer

A)  Cause the ribosomal subunits to dissociate. 
B)  Bind to the stop codons on the mRNA. 
C)  Carry GTP to provide energy for certain steps in the termination process. 
D)  Release the new peptide from the ribosome. 
E)  The termination factors do all of these. 
A)  Cause the ribosomal subunits to dissociate. 
B)  Bind to the stop codons on the mRNA. 
C)  Carry GTP to provide energy for certain steps in the termination process. 
D)  Release the new peptide from the ribosome. 
E)  The termination factors do all of these.

Question 17

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

Accepted Answer

A) True 
 B)False

Question 18

The amino acids are initially attached to either the 2' or 3' hydroxyl group of the tRNA.

Accepted Answer

A) True 
 B)False

Question 19

Under certain conditions, tRNAs can bind to the standard stop codons.

Accepted Answer

A) True 
 B)False

Question 20

N-formyl methionine

Accepted Answer

A)  can be found attached to every protein in E. coli. 
B)  can be found attached to some proteins in E. coli. 
C)  is never found on proteins in E. coli. 
A)  can be found attached to every protein in E. coli. 
B)  can be found attached to some proteins in E. coli. 
C)  is never found on proteins in E. coli.

Exam 12: Protein Synthesis: Translation of the Genetic Message

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

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

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

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

Wobble allows each codon to interact with more than one tRNA.

Activation of amino acids always takes place

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

Which of the following statements concerning tRNAs is false?

Which of the following is not true?

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

A polysome is

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

Which of the following statements concerning the genetic code is false?

Aminoacyl-tRNA Synthetases are involved in which step of translation?

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

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

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

The amino acids are initially attached to either the 2' or 3' hydroxyl group of the tRNA.

Under certain conditions, tRNAs can bind to the standard stop codons.

N-formyl methionine

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: 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

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