WGU C785 Biochemistry
test questions with 100%
correct answers
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 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.) - 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
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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 - 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.
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
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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.
Which level of protein structure is determined by the sequence of amino acids?
Secondary structure
Quaternary structure
Tertiary structure
Primary structure - correct answer✔️✔️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 - correct answer✔️✔️Hydrogen bonding
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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? - correct
answer✔️✔️Amino Acid structure 4
This is a polar, uncharged amino acid due to the OH group on the side chain.
Polar, uncharged amino acids containing oxygen or NH groups make hydrogen
bonds.
Which portion of the amino acid is inside the box?
The box is surrounding the section below the Alpha Carbon - correct
answer✔️✔️Side Chain
The side chain is the variable group of the amino acid, also called the R group.
Every amino acid has the same amino group, carboxylic acid group, and an
alpha carbon, but the side chain is different.
Which pair of amino acids will most likely interact through hydrophobic forces
between their side chains? - correct answer✔️✔️Both of these amino acids are
non-polar and therefore can interact together with a hydrophobic interaction.
Please note that the "S" in the amino acid on the right is non-polar, while the
"SH" group in answer choice D is polar. The S must have an H to be polar and
is otherwise non-polar.
Which portion of the amino acid is inside the box?
The box is over the Carbon at the Center of the chain - correct
answer✔️✔️Alpha Carbon
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