WGU C785 FINAL EXAM 2026 – 250 PRACTICE
QUESTIONS AND CORRECT ANSWERS WITH
RATIONALES
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) Primary
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
What is the complementary sequence to 3' ATG CGA ATA 5'?
A) 3' TAT TCG CAT 5'
,B) 3' TAC GCT TAT 5'
C) 5' ATA GCT TAC 3'
D) 5' TAT TCG CAT 3'
Correct Answer: B) 3' TAC GCT TAT 5'
Rationale: Complementary base pairing follows AT and CG rules. The
complementary strand runs antiparallel.
Question 3
A mutation in the beta hemoglobin gene results in the replacement of
glutamate (position 6) with valine, leading to sickle cell anemia. Which
replacement for valine would be expected to have the best clinical outcome?
A) Any nonpolar amino acid
B) Any positively charged amino acid
C) Any negatively charged amino acid
D) Any aromatic amino acid
Correct Answer: C) Any negatively charged amino acid
Rationale: The original amino acid in a healthy patient is glutamate, which is
negatively charged. The mutated amino acid is valine, which is nonpolar. The
best replacement would be one most like glutamate—a negatively charged
amino acid.
,Question 4
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) Primary structure
Rationale: The primary structure of a protein is simply the sequence of amino
acids held together by peptide bonds.
Question 5
Which force is most influential in determining the secondary structure of a
protein?
A) Hydrophobic effect
B) Disulfide bonding
C) Hydrogen bonding
D) Electrostatic interactions
Correct Answer: C) Hydrogen bonding
, Rationale: 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.
Question 6
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) Placement of the protein in a solution with a low pH
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 side chains in tertiary structure.
Question 7
What is the primary biochemical process that follows an increase in
betapleated sheet structure leading to amyloid deposit formation?
A) An increase in glycogen formation in brain cells
QUESTIONS AND CORRECT ANSWERS WITH
RATIONALES
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) Primary
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
What is the complementary sequence to 3' ATG CGA ATA 5'?
A) 3' TAT TCG CAT 5'
,B) 3' TAC GCT TAT 5'
C) 5' ATA GCT TAC 3'
D) 5' TAT TCG CAT 3'
Correct Answer: B) 3' TAC GCT TAT 5'
Rationale: Complementary base pairing follows AT and CG rules. The
complementary strand runs antiparallel.
Question 3
A mutation in the beta hemoglobin gene results in the replacement of
glutamate (position 6) with valine, leading to sickle cell anemia. Which
replacement for valine would be expected to have the best clinical outcome?
A) Any nonpolar amino acid
B) Any positively charged amino acid
C) Any negatively charged amino acid
D) Any aromatic amino acid
Correct Answer: C) Any negatively charged amino acid
Rationale: The original amino acid in a healthy patient is glutamate, which is
negatively charged. The mutated amino acid is valine, which is nonpolar. The
best replacement would be one most like glutamate—a negatively charged
amino acid.
,Question 4
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) Primary structure
Rationale: The primary structure of a protein is simply the sequence of amino
acids held together by peptide bonds.
Question 5
Which force is most influential in determining the secondary structure of a
protein?
A) Hydrophobic effect
B) Disulfide bonding
C) Hydrogen bonding
D) Electrostatic interactions
Correct Answer: C) Hydrogen bonding
, Rationale: 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.
Question 6
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) Placement of the protein in a solution with a low pH
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 side chains in tertiary structure.
Question 7
What is the primary biochemical process that follows an increase in
betapleated sheet structure leading to amyloid deposit formation?
A) An increase in glycogen formation in brain cells
