WGU C785 Biochemistry Unit Exam Questions &
Answers Latest 2024/2025 with complete solution
SECTION 1: PROTEIN STRUCTURE & AMINO ACIDS
Question 1
Which level of protein structure is disrupted through the hydrolysis of
peptide bonds?
A) Quaternary
B) Tertiary
C) Primary
D) Secondary
Correct Answer: C
Rationale: The primary structure of a protein is the sequence of
amino acids held together by peptide bonds. Peptide bonds are
formed by dehydration reactions and disrupted by hydrolysis.
Question 2
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. 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.)
A) 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.
B) The original amino acid in a healthy patient is glutamate, which is
positively charged. The mutated amino acid is valine, which is polar. The
best amino acid to replace valine would be any positively charged amino
acid.
C) The original amino acid in a healthy patient is glutamate, which is non-
polar. The mutated amino acid is valine, which is negatively charged. The
best amino acid to replace valine would be any non-polar amino acid.
D) The original amino acid in a healthy patient is glutamate, which is polar.
The mutated amino acid is valine, which is charged. The best amino acid to
replace valine would be any polar amino acid.
Correct Answer: A
Rationale: 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.
,Question 3
Secondary, tertiary, and quaternary levels of protein structure can all be
impacted by exposing a protein to which treatment?
A) Change of a hydrophobic amino acid to a different hydrophobic amino
acid
B) Addition of a reducing agent
C) Placement of the protein in a solution with a low pH
D) Increase in the concentration of the protein in solution
Correct Answer: C
Rationale: Changes in pH affect hydrogen bonds and ionic bonds.
Hydrogen bonds in the backbone of amino acids occur in secondary
structure, and both hydrogen bonds and ionic bonds occur in the
side chains of amino acids in tertiary structure.
Question 4
An increase in beta-pleated sheet structure in some brain proteins can
lead to an increase in amyloid deposit formation, characteristic of some
neurodegenerative diseases. What is the primary biochemical process
that follows the increase in beta-pleated sheet structure that leads to the
development of the amyloid deposits?
A) An increase in glycogen formation in the brain cells
B) Aggregation of the proteins in the brain
, C) Secretion of glucagon, leading to excessive ketogenesis
D) An increase in anaerobic metabolism of glucose in the brain
Correct Answer: B
Rationale: This question is describing changes in protein structure.
Aggregation occurs when proteins clump together inappropriately,
causing plaques like amyloid deposits to accumulate.
Question 5
Which level of protein structure is determined by the sequence of amino
acids?
A) Secondary structure
B) Quaternary structure
C) Tertiary structure
D) Primary structure
Correct Answer: D
Rationale: The primary structure of a protein is simply the sequence
of amino acids held together by peptide bonds.
Question 6
Which force is most influential in determining the secondary structure of
a protein?
Answers Latest 2024/2025 with complete solution
SECTION 1: PROTEIN STRUCTURE & AMINO ACIDS
Question 1
Which level of protein structure is disrupted through the hydrolysis of
peptide bonds?
A) Quaternary
B) Tertiary
C) Primary
D) Secondary
Correct Answer: C
Rationale: The primary structure of a protein is the sequence of
amino acids held together by peptide bonds. Peptide bonds are
formed by dehydration reactions and disrupted by hydrolysis.
Question 2
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. 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.)
A) 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.
B) The original amino acid in a healthy patient is glutamate, which is
positively charged. The mutated amino acid is valine, which is polar. The
best amino acid to replace valine would be any positively charged amino
acid.
C) The original amino acid in a healthy patient is glutamate, which is non-
polar. The mutated amino acid is valine, which is negatively charged. The
best amino acid to replace valine would be any non-polar amino acid.
D) The original amino acid in a healthy patient is glutamate, which is polar.
The mutated amino acid is valine, which is charged. The best amino acid to
replace valine would be any polar amino acid.
Correct Answer: A
Rationale: 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.
,Question 3
Secondary, tertiary, and quaternary levels of protein structure can all be
impacted by exposing a protein to which treatment?
A) Change of a hydrophobic amino acid to a different hydrophobic amino
acid
B) Addition of a reducing agent
C) Placement of the protein in a solution with a low pH
D) Increase in the concentration of the protein in solution
Correct Answer: C
Rationale: Changes in pH affect hydrogen bonds and ionic bonds.
Hydrogen bonds in the backbone of amino acids occur in secondary
structure, and both hydrogen bonds and ionic bonds occur in the
side chains of amino acids in tertiary structure.
Question 4
An increase in beta-pleated sheet structure in some brain proteins can
lead to an increase in amyloid deposit formation, characteristic of some
neurodegenerative diseases. What is the primary biochemical process
that follows the increase in beta-pleated sheet structure that leads to the
development of the amyloid deposits?
A) An increase in glycogen formation in the brain cells
B) Aggregation of the proteins in the brain
, C) Secretion of glucagon, leading to excessive ketogenesis
D) An increase in anaerobic metabolism of glucose in the brain
Correct Answer: B
Rationale: This question is describing changes in protein structure.
Aggregation occurs when proteins clump together inappropriately,
causing plaques like amyloid deposits to accumulate.
Question 5
Which level of protein structure is determined by the sequence of amino
acids?
A) Secondary structure
B) Quaternary structure
C) Tertiary structure
D) Primary structure
Correct Answer: D
Rationale: The primary structure of a protein is simply the sequence
of amino acids held together by peptide bonds.
Question 6
Which force is most influential in determining the secondary structure of
a protein?
