WGU C785 BIOCHEMISTRY UNIT EXAM QUESTIONS
1. 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.
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. 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 clin-
ical 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
1/
,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.
3. 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
2/
,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.
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
devel- opment 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.
5. Which level of protein structure is determined by the sequence of
amino acids?
3/
, 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.
6. Which force is most influential in determining the secondary structure
of a protein?
4/
1. 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.
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. 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 clin-
ical 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
1/
,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.
3. 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
2/
,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.
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
devel- opment 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.
5. Which level of protein structure is determined by the sequence of
amino acids?
3/
, 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.
6. Which force is most influential in determining the secondary structure
of a protein?
4/
