WGU C785 Biochemistry Unit Exam
Questions and Answers Rated A
Which level of protein structure is disrupted through the hydrolysis of peptide bonds?
Quaternary
Tertiary
Primary
Secondary ✔✔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 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.) ✔✔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 ✔✔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.
,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 ✔✔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
, Tertiary structure
Primary structure ✔✔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 ✔✔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? ✔✔Amino Acid structure 4
Questions and Answers Rated A
Which level of protein structure is disrupted through the hydrolysis of peptide bonds?
Quaternary
Tertiary
Primary
Secondary ✔✔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 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.) ✔✔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 ✔✔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.
,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 ✔✔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
, Tertiary structure
Primary structure ✔✔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 ✔✔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? ✔✔Amino Acid structure 4
