ESSENTIAL CELL BIOLOGY, FOURTH
EDITION CHAPTER 7 FROM DNA TO
PROTEIN EXAM QUESTIONS AND
ANSWERS
The sigma subunit of bacterial RNA polymerase ___________________. - ANSWER-
recognizes promoter sites in the DNA.
There are several reasons why the primase used to make the RNA primer for DNA
replication is not suitable for gene transcription. Which of the statements below is not
one
of those reasons? - ANSWER-Primase can initiate RNA synthesis without the need for
a base-paired primer.
You have a bacterial strain with a mutation that removes the transcription termination
signal from the Abd operon. Which of the following statements describes the most likely
effect of this mutation on Abd transcription? - ANSWER-The Abd RNA from the mutant
strain will be longer than normal.
Transcription in bacteria differs from transcription in a eukaryotic cell because
__________________________. - ANSWER-RNA polymerase (along with its sigma
subunit) can initiate transcription on its
own.
Which of the following does not occur before a eukaryotic mRNA is exported from the
nucleus? - ANSWER-The ribosome binds to the mRNA.
Total nucleic acids are extracted from a culture of yeast cells and are then mixed with
resin beads to which the polynucleotide 5′-TTTTTTTTTTTTTTTTTTTTTTTTT-3′ has
been covalently attached. After a short incubation, the beads are then extracted from
the
mixture. When you analyze the cellular nucleic acids that have stuck to the beads,
which
of the following is most abundant? - ANSWER-mRNA
Which of the following statements about RNA splicing is false? - ANSWER-For a gene
to function properly, every exon must be removed from the primary
transcript in the same fashion on every mRNA molecule produced from the same
gene.
Genes in eukaryotic cells often have intronic sequences coded for within the DNA.
These
, sequences are ultimately not translated into proteins. Why? - ANSWER-Introns are
removed by catalytic RNAs in the cytoplasm.
snRNAs ___________________. - ANSWER-can bind to specific sequences at intron-
exon boundaries through complementary
base-pairing.
Which of the following statements about the genetic code is correct? - ANSWER-The
genetic code is redundant.
The piece of RNA below includes the region that codes for the binding site for the
initiator tRNA needed in translation.
5′-GUUUCCCGUAUACAUGCGUGCCGGGGGC-3′
Which amino acid will be on the tRNA that is the first to bind to the A site of the
ribosome? - ANSWER-arginine
Which amino acid would you expect a tRNA with the anticodon 5′-CUU-3′ to carry? -
ANSWER-lysine
Below is the sequence from the 3′ end of an mRNA.
5′-CCGUUACCAGGCCUCAUUAUUGGUAACGGAAAAAAAAAAAAAA-3′
If you were told that this sequence contains the stop codon for the protein encoded by
this
mRNA, what is the anticodon on the tRNA in the P site of the ribosome when release
factor binds to the A site? - ANSWER-5′-CCA-3′ from UGG
A strain of yeast translates mRNA into protein inaccurately. Individual molecules of a
particular protein isolated from this yeast have variations in the first 11 amino acids
compared with the sequence of the same protein isolated from normal yeast cells, as
listed in Figure Q7-45. What is the most likely cause of this variation in protein
sequence? - ANSWER-a mutation in the isoleucyl-tRNA synthetase that decreases its
ability to
distinguish between different amino acids
A mutation in the tRNA for the amino acid lysine results in the anticodon sequence 5′-
UAU-3′ (instead of 5′-UUU-3′). Which of the following aberrations in protein synthesis
might this tRNA cause? - ANSWER-substitution of lysine for isoleucine
What do you predict would happen if you created a tRNA with an anticodon of 5′-CAA-3′
that is charged with methionine, and added this modified tRNA to a cell-free translation
system that has all the normal components required for translating RNAs? - ANSWER-
methionine would be incorporated into proteins at some positions where leucine
should be
The ribosome is important for catalyzing the formation of peptide bonds. Which of the
EDITION CHAPTER 7 FROM DNA TO
PROTEIN EXAM QUESTIONS AND
ANSWERS
The sigma subunit of bacterial RNA polymerase ___________________. - ANSWER-
recognizes promoter sites in the DNA.
There are several reasons why the primase used to make the RNA primer for DNA
replication is not suitable for gene transcription. Which of the statements below is not
one
of those reasons? - ANSWER-Primase can initiate RNA synthesis without the need for
a base-paired primer.
You have a bacterial strain with a mutation that removes the transcription termination
signal from the Abd operon. Which of the following statements describes the most likely
effect of this mutation on Abd transcription? - ANSWER-The Abd RNA from the mutant
strain will be longer than normal.
Transcription in bacteria differs from transcription in a eukaryotic cell because
__________________________. - ANSWER-RNA polymerase (along with its sigma
subunit) can initiate transcription on its
own.
Which of the following does not occur before a eukaryotic mRNA is exported from the
nucleus? - ANSWER-The ribosome binds to the mRNA.
Total nucleic acids are extracted from a culture of yeast cells and are then mixed with
resin beads to which the polynucleotide 5′-TTTTTTTTTTTTTTTTTTTTTTTTT-3′ has
been covalently attached. After a short incubation, the beads are then extracted from
the
mixture. When you analyze the cellular nucleic acids that have stuck to the beads,
which
of the following is most abundant? - ANSWER-mRNA
Which of the following statements about RNA splicing is false? - ANSWER-For a gene
to function properly, every exon must be removed from the primary
transcript in the same fashion on every mRNA molecule produced from the same
gene.
Genes in eukaryotic cells often have intronic sequences coded for within the DNA.
These
, sequences are ultimately not translated into proteins. Why? - ANSWER-Introns are
removed by catalytic RNAs in the cytoplasm.
snRNAs ___________________. - ANSWER-can bind to specific sequences at intron-
exon boundaries through complementary
base-pairing.
Which of the following statements about the genetic code is correct? - ANSWER-The
genetic code is redundant.
The piece of RNA below includes the region that codes for the binding site for the
initiator tRNA needed in translation.
5′-GUUUCCCGUAUACAUGCGUGCCGGGGGC-3′
Which amino acid will be on the tRNA that is the first to bind to the A site of the
ribosome? - ANSWER-arginine
Which amino acid would you expect a tRNA with the anticodon 5′-CUU-3′ to carry? -
ANSWER-lysine
Below is the sequence from the 3′ end of an mRNA.
5′-CCGUUACCAGGCCUCAUUAUUGGUAACGGAAAAAAAAAAAAAA-3′
If you were told that this sequence contains the stop codon for the protein encoded by
this
mRNA, what is the anticodon on the tRNA in the P site of the ribosome when release
factor binds to the A site? - ANSWER-5′-CCA-3′ from UGG
A strain of yeast translates mRNA into protein inaccurately. Individual molecules of a
particular protein isolated from this yeast have variations in the first 11 amino acids
compared with the sequence of the same protein isolated from normal yeast cells, as
listed in Figure Q7-45. What is the most likely cause of this variation in protein
sequence? - ANSWER-a mutation in the isoleucyl-tRNA synthetase that decreases its
ability to
distinguish between different amino acids
A mutation in the tRNA for the amino acid lysine results in the anticodon sequence 5′-
UAU-3′ (instead of 5′-UUU-3′). Which of the following aberrations in protein synthesis
might this tRNA cause? - ANSWER-substitution of lysine for isoleucine
What do you predict would happen if you created a tRNA with an anticodon of 5′-CAA-3′
that is charged with methionine, and added this modified tRNA to a cell-free translation
system that has all the normal components required for translating RNAs? - ANSWER-
methionine would be incorporated into proteins at some positions where leucine
should be
The ribosome is important for catalyzing the formation of peptide bonds. Which of the
