WGU C785 BIOCHEMISTRY UNIT
BANK; COMPLETE ACCURATE
QUIZZES WITH VERIFIED ANSWERS
A final product of a four-step metabolic pathway serves as
a noncompetitive inhibitor, binding to an enzyme in this
pathway and temporarily turning off the pathway. Which
enzyme is most likely to be targeted by the inhibitor?
The final enzyme in the pathway
The first enzyme in the pathway
Any enzyme in the middle of the pathway
The second enzyme in the pathway - correct
answer- The first enzyme in the pathway
,The final product's structure is more unlike the substrate
for the first enzyme in the pathway than any other, and
thus the least likely to fit the active site of enzyme 1.
A mutation in the beta-hemoglobin gene, which results in
the replacement of the amino acid glutamate in position 6
with the amino acid valine, leads to the development of
sickle cell anemia. The structures of glutamate and valine
are shown below.
If the beta hemoglobin gene in a patient with sickle-cell
anemia were to be edited so that the valine in position 6
was replaced with a different amino acid, which
replacement for valine would be expected to have the
best clinical outcome, in theory, for the patient? (Assume
the valine can potentially be replaced with any amino acid
other than glutamate.) - correct answer- The
original amino acid in a healthy patient is glutamate,
which is negatively charged. The mutated amino acid is
valine, which is non-polar. Valine is causing sickle cell
anemia. The best amino acid to replace valine so that the
patient is healthy again would be the one most like
glutamate, so any negatively charged amino acid.
,A patient has received a large dose of ionizing radiation at
his place of employment. Which scenario is accurate?
Ligase removes a single damaged base and replaces it
with a new nucleotide.
Double-stranded DNA breaks are being repaired by
nonhomologous end joining, without the use of a
homologous template.
The homologous recombination pathway is upregulated
and is facilitating the removal of mismatched bases.
A string of damaged nucleotides is removed and replaced
by a new nucleotide sequence in the base excision repair
pathway. - correct answer- Double-stranded
DNA breaks are being repaired by nonhomologous end
joining, without the use of a homologous template.
, Due to the large dose of ionizing radiation, the patient has
many double-stranded DNA breaks, and undamaged
homologous DNA is in short supply. Nonhomologous end-
joining will be used to fix these double-strand breaks.
A point mutation has altered the amino acid sequence of
a neuronal tau protein, causing serine (Ser) at position
202 to be mutated to proline (Pro). Which set of codons
below corresponds to this mutation?
TCT to CCT
AGA to GGA
CGA to AGG
AGG to CCC - correct answer- TCT to CCT
TCT is a codon for Ser, and CCT is a codon for Pro. TCT to
CCT is a point mutation that changes Ser to Pro.
BANK; COMPLETE ACCURATE
QUIZZES WITH VERIFIED ANSWERS
A final product of a four-step metabolic pathway serves as
a noncompetitive inhibitor, binding to an enzyme in this
pathway and temporarily turning off the pathway. Which
enzyme is most likely to be targeted by the inhibitor?
The final enzyme in the pathway
The first enzyme in the pathway
Any enzyme in the middle of the pathway
The second enzyme in the pathway - correct
answer- The first enzyme in the pathway
,The final product's structure is more unlike the substrate
for the first enzyme in the pathway than any other, and
thus the least likely to fit the active site of enzyme 1.
A mutation in the beta-hemoglobin gene, which results in
the replacement of the amino acid glutamate in position 6
with the amino acid valine, leads to the development of
sickle cell anemia. The structures of glutamate and valine
are shown below.
If the beta hemoglobin gene in a patient with sickle-cell
anemia were to be edited so that the valine in position 6
was replaced with a different amino acid, which
replacement for valine would be expected to have the
best clinical outcome, in theory, for the patient? (Assume
the valine can potentially be replaced with any amino acid
other than glutamate.) - correct answer- The
original amino acid in a healthy patient is glutamate,
which is negatively charged. The mutated amino acid is
valine, which is non-polar. Valine is causing sickle cell
anemia. The best amino acid to replace valine so that the
patient is healthy again would be the one most like
glutamate, so any negatively charged amino acid.
,A patient has received a large dose of ionizing radiation at
his place of employment. Which scenario is accurate?
Ligase removes a single damaged base and replaces it
with a new nucleotide.
Double-stranded DNA breaks are being repaired by
nonhomologous end joining, without the use of a
homologous template.
The homologous recombination pathway is upregulated
and is facilitating the removal of mismatched bases.
A string of damaged nucleotides is removed and replaced
by a new nucleotide sequence in the base excision repair
pathway. - correct answer- Double-stranded
DNA breaks are being repaired by nonhomologous end
joining, without the use of a homologous template.
, Due to the large dose of ionizing radiation, the patient has
many double-stranded DNA breaks, and undamaged
homologous DNA is in short supply. Nonhomologous end-
joining will be used to fix these double-strand breaks.
A point mutation has altered the amino acid sequence of
a neuronal tau protein, causing serine (Ser) at position
202 to be mutated to proline (Pro). Which set of codons
below corresponds to this mutation?
TCT to CCT
AGA to GGA
CGA to AGG
AGG to CCC - correct answer- TCT to CCT
TCT is a codon for Ser, and CCT is a codon for Pro. TCT to
CCT is a point mutation that changes Ser to Pro.
