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WGU C785 BIOCHEMISTR Y UNIT
EXAM QUESTIONS & ANS WERS
LATEST WITH COMPLETE
SOLUTION
Question : Which level of protein structure is disrupted
through the hydrolysis of peptide bonds?
Quaternary
Tertiary
Primary
Secondary
Correct answer: Primary
The primary structure of a protein is the sequence of amino acids held together by peptide bonds. Peptide
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bonds are formed by dehydration reactions and disrupted by hydrolysis.
Question : 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.
Question : Secondary, tertiary, and quaternary levels of
protein structure can all be impacted by exposing a protein to which treatment?
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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
Correct 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.
Question : An increase in beta-pleated sheet structure in
some brain proteins can lead to an increase in amyloid deposit formation, characteristic of some
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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
Correct 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.