Question 1

Amino acids linked to the 2'-end of a tRNA

Accepted Answer

A)  are regular substrates for protein synthesis. 
B)  are transferred to the 3' position prior to their use in protein synthesis. 
C)  are prompted hydrolysed off as part of a proofreading mechanism. 
D)  never occur. 
A)  are regular substrates for protein synthesis. 
B)  are transferred to the 3' position prior to their use in protein synthesis. 
C)  are prompted hydrolysed off as part of a proofreading mechanism. 
D)  never occur.

Question 2

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 3

Which of the following codons does not code for an amino acid?

Accepted Answer

A)  AUG 
B)  UAA 
C)  CAU 
D)  GUU 
E)  All of these code for an amino acid 
A)  AUG 
B)  UAA 
C)  CAU 
D)  GUU 
E)  All of these code for an amino acid

Question 4

The formylation of methionine in prokaryotes

Accepted Answer

A)  depends on two different tRNAs, where methionine can be formylated when bound to one form and not the other. 
B)  depends on two different tRNAs, where methionine can be formylated when bound to either one. 
C)  depends on one tRNA, where methionine is formylated after binding. 
D)  takes place before methionine is bound to tRNA. 
A)  depends on two different tRNAs, where methionine can be formylated when bound to one form and not the other. 
B)  depends on two different tRNAs, where methionine can be formylated when bound to either one. 
C)  depends on one tRNA, where methionine is formylated after binding. 
D)  takes place before methionine is bound to tRNA.

Question 5

Which of the following best describes the assembly process to initiate translation in prokaryotes?

Accepted Answer

A)  small ribosome subunit associates with large subunit; mRNA associates next; IFs bring in first f-Met-tRNA; bound NTP hydrolyzed. 
B)  IF binds f-Met-tRNA; small ribosome subunit associates next; mRNA associates next; then large subunit; bound NTP hydrolyzed. 
C)  IF w\ bound NTP binds f-Met-tRNA; mRNA associates next; small subunit associates next; bound NTP hydrolyzed; large subunit associates. 
D)  small subunit associates with mRNA; IF w\ bound NTP brings in first f-Met-tRNA; IF then hydrolyses bound NTP; large subunit associates 
A)  small ribosome subunit associates with large subunit; mRNA associates next; IFs bring in first f-Met-tRNA; bound NTP hydrolyzed. 
B)  IF binds f-Met-tRNA; small ribosome subunit associates next; mRNA associates next; then large subunit; bound NTP hydrolyzed. 
C)  IF w\ bound NTP binds f-Met-tRNA; mRNA associates next; small subunit associates next; bound NTP hydrolyzed; large subunit associates. 
D)  small subunit associates with mRNA; IF w\ bound NTP brings in first f-Met-tRNA; IF then hydrolyses bound NTP; large subunit associates

Question 6

At what point does the formylation reaction take place to produce N -formylmethionine?

Accepted Answer

A)  On the free amino acid prior to its addition to a tRNA. 
B)  After methionine has been added to a specific tRNA. 
C)  After the methionine-tRNA adduct has complexed with the ribosome. 
D)  After the first peptide bond is formed on the ribosome. 
A)  On the free amino acid prior to its addition to a tRNA. 
B)  After methionine has been added to a specific tRNA. 
C)  After the methionine-tRNA adduct has complexed with the ribosome. 
D)  After the first peptide bond is formed on the ribosome.

Question 7

Each tRNA molecule has a separate activating enzyme.

Accepted Answer

A) True 
 B)False

Question 8

The ribosome is actually a ribozyme.

Accepted Answer

A) True 
 B)False

Question 9

Which of the following is not a key advantage of wobble in the codon-anticodon reaction?

Accepted Answer

A)  It allows for fewer tRNAs in the cell. 
B)  It allows for making more than one protein from the same coding sequence. 
C)  It allows for a certain amount of mutation in the mRNA without affecting the protein sequence. 
D)  All of these are advantages of wobble. 
A)  It allows for fewer tRNAs in the cell. 
B)  It allows for making more than one protein from the same coding sequence. 
C)  It allows for a certain amount of mutation in the mRNA without affecting the protein sequence. 
D)  All of these are advantages of wobble.

Question 10

Using the genetic code, indicate which polypeptides would be synthesized if poly (UGG) were used as a synthetic mRNA?

Accepted Answer

A)  poly(gly) 
B)  poly(trp) 
C)  poly(trp-val-gly) 
D)  poly(trp), poly(val), poly(gly) 
A)  poly(gly) 
B)  poly(trp) 
C)  poly(trp-val-gly) 
D)  poly(trp), poly(val), poly(gly)

Question 11

A tRNA was determined to have the following anticodon sequence:
3' − GAI − 5' (I represents the base hypoxanthine)
Which of the following codons can form base pairs with this anticodon?

Accepted Answer

A)  5' − CUA − 3' 
B)  5' − CUC − 3' 
C)  5' − CUU − 3' 
D)  all of these 
A)  5' − CUA − 3' 
B)  5' − CUC − 3' 
C)  5' − CUU − 3' 
D)  all of these

Question 12

The template for protein synthesis is:

Accepted Answer

A)  a mRNA strand 
B)  the DNA coding strand 
C)  the DNA template strand 
D)  a protein primer 
E)  none of these 
A)  a mRNA strand 
B)  the DNA coding strand 
C)  the DNA template strand 
D)  a protein primer 
E)  none of these

Question 13

Which of the following is not true concerning silent mutations?

Accepted Answer

A)  Silent mutations refer to base sequence differences that do not change the amino acid coded for 
B)  Only changes in base sequence that lead to a different amino acid can have an effect on the organism 
C)  Changes in the sequence of an exonic splicing enhancers can lead faulty removal of introns 
D)  Silent mutations in a gene for pain tolerance has been correlated with human differences in perception of pain 
A)  Silent mutations refer to base sequence differences that do not change the amino acid coded for 
B)  Only changes in base sequence that lead to a different amino acid can have an effect on the organism 
C)  Changes in the sequence of an exonic splicing enhancers can lead faulty removal of introns 
D)  Silent mutations in a gene for pain tolerance has been correlated with human differences in perception of pain

Question 14

​ The maximum number of possible triplets of the four bases occurring in RNA, which are used to encode 20 amino acids, is _____.

Accepted Answer

A) f orty-two 
B) t wenty-four 
C) f orty-six 
D) s ixty-four 
A) f orty-two 
B) t wenty-four 
C) f orty-six 
D) s ixty-four

Question 15

A Shine-Dalgarno Sequence is a

Accepted Answer

A)  sequence of nucleotides in the DNA that interacts with the σ -subunit of RNA polymerase to begin transcription. 
B)  sequence of nucleotides in an mRNA that interacts with the small subunit of a ribosome to begin translation. 
C)  sequence of nucleotides in the DNA that interacts with ρ -protein to terminate transcription. 
D)  sequence of nucleotides in an mRNA that functions to terminate translation. 
A)  sequence of nucleotides in the DNA that interacts with the σ -subunit of RNA polymerase to begin transcription. 
B)  sequence of nucleotides in an mRNA that interacts with the small subunit of a ribosome to begin translation. 
C)  sequence of nucleotides in the DNA that interacts with ρ -protein to terminate transcription. 
D)  sequence of nucleotides in an mRNA that functions to terminate translation.

Question 16

During elongation, tRNA binds initially to the

Accepted Answer

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

Question 17

Which of following best describes the two-step process for adding amino acids to tRNAs?
AA = amino acid, Pi = phosphate, PPi = pyrophosphate

Accepted Answer

A)  AA + ATP → AA − P + ADP; AA − P + tRNA → AA − tRNA + Pi 
B)  AA + ATP → AA − AMP + PPi; AA − AMP + tRNA → AA − tRNA + AMP 
C)  tRNA + ATP → tRNA − P + ADP; tRNA − P + AA → AA − tRNA + Pi 
D)  tRNA + ATP → tRNA − AMP + PPi; tRNA − AMP + AA → AA − tRNA + AMP 
A)  AA + ATP → AA − P + ADP; AA − P + tRNA → AA − tRNA + Pi 
B)  AA + ATP → AA − AMP + PPi; AA − AMP + tRNA → AA − tRNA + AMP 
C)  tRNA + ATP → tRNA − P + ADP; tRNA − P + AA → AA − tRNA + Pi 
D)  tRNA + ATP → tRNA − AMP + PPi; tRNA − AMP + AA → AA − tRNA + AMP

Question 18

The process of amino acid activation

Accepted Answer

A)  involves the formation of a peptide bond between the amino acid and tRNA 
B)  takes place by formation of a mixed anhydride of the amino acid and tRNA 
C)  involves the formation of an ester bond between the amino acid and tRNA 
D)  none of these 
A)  involves the formation of a peptide bond between the amino acid and tRNA 
B)  takes place by formation of a mixed anhydride of the amino acid and tRNA 
C)  involves the formation of an ester bond between the amino acid and tRNA 
D)  none of these

Question 19

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 20

Activation of amino acids

Accepted Answer

A)  produces a pyrophosphate byproduct. 
B)  produces an inorganic phosphate. 
C)  produces a cyclic AMP. 
D)  does not involve the release of energy. 
A)  produces a pyrophosphate byproduct. 
B)  produces an inorganic phosphate. 
C)  produces a cyclic AMP. 
D)  does not involve the release of energy.

Exam 12: Protein Synthesis Translation of the Genetic Message

Amino acids linked to the 2'-end of a tRNA

A polysome is

Which of the following codons does not code for an amino acid?

The formylation of methionine in prokaryotes

Which of the following best describes the assembly process to initiate translation in prokaryotes?

At what point does the formylation reaction take place to produce N -formylmethionine?

Each tRNA molecule has a separate activating enzyme.

The ribosome is actually a ribozyme.

Which of the following is not a key advantage of wobble in the codon-anticodon reaction?

Using the genetic code, indicate which polypeptides would be synthesized if poly (UGG) were used as a synthetic mRNA?

A tRNA was determined to have the following anticodon sequence: 3' − GAI − 5' (I represents the base hypoxanthine) Which of the following codons can form base pairs with this anticodon?

The template for protein synthesis is:

Which of the following is not true concerning silent mutations?

​ The maximum number of possible triplets of the four bases occurring in RNA, which are used to encode 20 amino acids, is _____.

A Shine-Dalgarno Sequence is a

During elongation, tRNA binds initially to the

Which of following best describes the two-step process for adding amino acids to tRNAs? AA = amino acid, Pi = phosphate, PPi = pyrophosphate

The process of amino acid activation

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

Activation of amino acids

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

The maximum number of possible triplets of the four bases occurring in RNA, which are used to encode 20 amino acids, is _____.

Which of following best describes the two-step process for adding amino acids to tRNAs? AA = amino acid, P_i = phosphate, PP_i = pyrophosphate