WGU 785 (C785 Biochemistry) Final
Exam Practice – Western Governors
University (WGU) – 2026/2027
Academic Year – Verified Questions
and Answers for Professional Business
and Leadership Students
SECTION 1: PROTEIN STRUCTURE & AMINO ACIDS
Q1: Which level of protein structure is disrupted through the hydrolysis of peptide
bonds?
A) Quaternary structure
B) Tertiary structure
C) Primary structure
D) Secondary structure
Answer: C) Primary structure
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. Secondary, tertiary, and quaternary structures are maintained by
,non-covalent interactions (hydrogen bonds, ionic bonds, hydrophobic interactions,
disulfide bonds), not peptide bonds themselves .
Q2: 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
Answer: D) Primary structure
Rationale: The primary structure of a protein is simply the sequence of amino acids held
together by peptide bonds. This sequence determines how the protein will fold into
higher-order structures .
Q3: 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
Answer: C) Hydrogen bonding
,Rationale: The secondary structure of a protein (α-helices and β-pleated sheets) is built
by hydrogen bonds between the carboxyl groups and amino groups on the backbones
of the amino acids .
Q4: Which amino acid would most likely participate in hydrogen bonds?
A) Valine
B) Leucine
C) Serine
D) Phenylalanine
Answer: C) Serine
Rationale: Serine is a polar, uncharged amino acid due to the OH group on its side
chain. Polar, uncharged amino acids containing oxygen or NH groups make hydrogen
bonds. Valine, leucine, and phenylalanine are non-polar hydrophobic amino acids .
Q5: Which portion of an amino acid is the variable group that differs between
amino acids?
A) The amino group
B) The carboxyl group
C) The alpha carbon
D) The side chain (R group)
Answer: D) The side chain (R group)
, Rationale: The side chain (R group) is the variable group of the amino acid. Every amino
acid has the same amino group, carboxylic acid group, and alpha carbon, but the side
chain differs, giving each amino acid its unique properties .
Q6: A mutation in the beta-hemoglobin gene results in the replacement of
glutamate (position 6) with valine, leading to sickle cell anemia. If the gene were
edited to replace valine with a different amino acid, which replacement would
have the best clinical outcome?
A) Any non-polar amino acid
B) Any positively charged amino acid
C) Any negatively charged amino acid
D) Any hydrophobic amino acid
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 non-polar. The best replacement
would be one most like glutamate—any negatively charged amino acid .
Q7: Which pair of amino acids will most likely interact through hydrophobic forces
between their side chains?
A) Two polar amino acids
B) Two charged amino acids
C) Two non-polar amino acids
D) One polar and one non-polar amino acid
Exam Practice – Western Governors
University (WGU) – 2026/2027
Academic Year – Verified Questions
and Answers for Professional Business
and Leadership Students
SECTION 1: PROTEIN STRUCTURE & AMINO ACIDS
Q1: Which level of protein structure is disrupted through the hydrolysis of peptide
bonds?
A) Quaternary structure
B) Tertiary structure
C) Primary structure
D) Secondary structure
Answer: C) Primary structure
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. Secondary, tertiary, and quaternary structures are maintained by
,non-covalent interactions (hydrogen bonds, ionic bonds, hydrophobic interactions,
disulfide bonds), not peptide bonds themselves .
Q2: 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
Answer: D) Primary structure
Rationale: The primary structure of a protein is simply the sequence of amino acids held
together by peptide bonds. This sequence determines how the protein will fold into
higher-order structures .
Q3: 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
Answer: C) Hydrogen bonding
,Rationale: The secondary structure of a protein (α-helices and β-pleated sheets) is built
by hydrogen bonds between the carboxyl groups and amino groups on the backbones
of the amino acids .
Q4: Which amino acid would most likely participate in hydrogen bonds?
A) Valine
B) Leucine
C) Serine
D) Phenylalanine
Answer: C) Serine
Rationale: Serine is a polar, uncharged amino acid due to the OH group on its side
chain. Polar, uncharged amino acids containing oxygen or NH groups make hydrogen
bonds. Valine, leucine, and phenylalanine are non-polar hydrophobic amino acids .
Q5: Which portion of an amino acid is the variable group that differs between
amino acids?
A) The amino group
B) The carboxyl group
C) The alpha carbon
D) The side chain (R group)
Answer: D) The side chain (R group)
, Rationale: The side chain (R group) is the variable group of the amino acid. Every amino
acid has the same amino group, carboxylic acid group, and alpha carbon, but the side
chain differs, giving each amino acid its unique properties .
Q6: A mutation in the beta-hemoglobin gene results in the replacement of
glutamate (position 6) with valine, leading to sickle cell anemia. If the gene were
edited to replace valine with a different amino acid, which replacement would
have the best clinical outcome?
A) Any non-polar amino acid
B) Any positively charged amino acid
C) Any negatively charged amino acid
D) Any hydrophobic amino acid
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 non-polar. The best replacement
would be one most like glutamate—any negatively charged amino acid .
Q7: Which pair of amino acids will most likely interact through hydrophobic forces
between their side chains?
A) Two polar amino acids
B) Two charged amino acids
C) Two non-polar amino acids
D) One polar and one non-polar amino acid
