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WGU Biochemistry OA (Latest 2026/2027)
Verified Answers
Which level of protein structure is disrupted through the hydrolysis of
peptide bonds?
Quaternary
Tertiary
Primary
Secondary ......ANSWER.....Primary
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.
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
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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.)
......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.
Secondary, tertiary, and quaternary levels of protein structure can all be
impacted by exposing a protein to which treatment?
Change of a hydrophobic amino acid to a different hydrophobic amino acid
Addition of a reducing agent
Placement of the protein in a solution with a low pH
Increase in the concentration of the protein in solution
......ANSWER.....Placement of the protein in a solution with a low pH
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.
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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?
An increase in glycogen formation in the brain cells
Aggregation of the proteins in the brain
Secretion of glucagon, leading to excessive ketogenesis
An increase in anaerobic metabolism of glucose in the brain
......ANSWER.....Aggregation of the proteins in the brain
This question is describing changes in protein structure. Aggregation occurs
when proteins clump together inappropriately, causing plaques like amyloid
deposits to accumulate.
Which level of protein structure is determined by the sequence of amino
acids?
Secondary structure
Quaternary structure
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Tertiary structure
Primary structure ......ANSWER.....Primary structure
The primary structure of a protein is simply the sequence of amino acids
held together by peptide bonds.
Which force is most influential in determining the secondary structure of a
protein?
Hydrophobic effect
Disulfide bonding
Hydrogen bonding
Electrostatic interactions ......ANSWER.....Hydrogen bonding
The secondary structure of a protein is built by hydrogen bonds between the
carboxyl groups and amino groups on the backbones of the amino acids.
Which amino acid would most likely participate in hydrogen bonds?
......ANSWER.....Amino Acid structure 4
WGU Biochemistry OA (Latest 2026/2027)
Verified Answers
Which level of protein structure is disrupted through the hydrolysis of
peptide bonds?
Quaternary
Tertiary
Primary
Secondary ......ANSWER.....Primary
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.
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
,2|Page
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.)
......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.
Secondary, tertiary, and quaternary levels of protein structure can all be
impacted by exposing a protein to which treatment?
Change of a hydrophobic amino acid to a different hydrophobic amino acid
Addition of a reducing agent
Placement of the protein in a solution with a low pH
Increase in the concentration of the protein in solution
......ANSWER.....Placement of the protein in a solution with a low pH
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.
,3|Page
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?
An increase in glycogen formation in the brain cells
Aggregation of the proteins in the brain
Secretion of glucagon, leading to excessive ketogenesis
An increase in anaerobic metabolism of glucose in the brain
......ANSWER.....Aggregation of the proteins in the brain
This question is describing changes in protein structure. Aggregation occurs
when proteins clump together inappropriately, causing plaques like amyloid
deposits to accumulate.
Which level of protein structure is determined by the sequence of amino
acids?
Secondary structure
Quaternary structure
, 4|Page
Tertiary structure
Primary structure ......ANSWER.....Primary structure
The primary structure of a protein is simply the sequence of amino acids
held together by peptide bonds.
Which force is most influential in determining the secondary structure of a
protein?
Hydrophobic effect
Disulfide bonding
Hydrogen bonding
Electrostatic interactions ......ANSWER.....Hydrogen bonding
The secondary structure of a protein is built by hydrogen bonds between the
carboxyl groups and amino groups on the backbones of the amino acids.
Which amino acid would most likely participate in hydrogen bonds?
......ANSWER.....Amino Acid structure 4
