WGU C785
BIOCHEMISTRY
UNIT EXAM
QUESTIONS
Which level of protein structure is disrupted through the hydrolysis of peptide bonds?
Quaternary
Tertiary
Primary
Secondary - Answers -Primary
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? - Answers -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 - Answers -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? - Answers -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 - Answers -Alpha Carbon
The alpha carbon is the central carbon on an amino acid that holds together the other
groups of the amino acid. It is always attached to the amino group, the carboxyl group,
the side chain, and a single hydrogen. It is part of the backbone of the amino acid and is
found in every amino acid.
Given the following amino acid structure, what is the strongest intermolecular force it
would participate in to stabilize a protein structure?
Ionic bond
Disulfide bond
Hydrogen bond
Hydrophobic interaction - Answers -Hydrophobic interaction
The amino acid pictured only has CH groups in its side chain, and therefore is non-
polar. Non-polar amino acids make hydrophobic interactions.
Which change would most likely result in a permanent modification of an expressed
protein's function?
An increase in the pH of a solution in which a protein is dissolved from 6.5 to 8.0, when
it is known that the protein has an optimal activity of pH 7.8
A mutation of the gene for a protein that leads to the substitution of a hydrophobic
amino acid with a nonpolar amino acid
A mutation of the gene for a protein that leads to the substitution of a nonpolar amino
acid with a charged amino acid
The mutation of a gene for an enzyme involved in protein synthesis following exposure
to X-rays, causing the protein not to be synthesized - Answers -A mutation of the gene
for a protein that leads to the substitution of a nonpolar amino acid with a charged
amino acid.
, The mutation of nonpolar amino acid to a charged amino acid will disrupt the original
hydrophobic interaction, permanently changing the function of the protein.
Which property of enzymes is illustrated in the final step of the enzymatic cycle?
Enzymes are specific.
Enzymes increase the reaction rate for a reaction.
Enzymes are reusable.
Enzymes lower the activation energy for a reaction. - Answers -Enzymes are reusable.
In the final step of the enzymatic cycle, the product is released and the enzyme is able
to bind to a new substrate and begin the cycle again.
In the enzyme cycle, which step immediately follows induced fit?
Formation of the enzyme-substrate complex
Release of the product and enzyme complex
Formation of the enzyme-molecule complex
Formation of the enzyme-product complex - Answers -Formation of the enzyme-product
complex
The induced fit refers to the conformational change that the enzyme undergoes when it
binds to the substrate to form the enzyme-substrate complex. Therefore, the enzymatic
cycle step that occurs after the induced fit is the formation of the enzyme-product
complex.
Which type of inhibition occurs when a particular drug binds to the active site of an
enzyme?
Competitive
Uncompetitive
Irreversible
Noncompetitive - Answers -Competitive
Competitive inhibitors compete with the substrate to bind to the active site of the
enzyme.
BIOCHEMISTRY
UNIT EXAM
QUESTIONS
Which level of protein structure is disrupted through the hydrolysis of peptide bonds?
Quaternary
Tertiary
Primary
Secondary - Answers -Primary
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? - Answers -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 - Answers -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? - Answers -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 - Answers -Alpha Carbon
The alpha carbon is the central carbon on an amino acid that holds together the other
groups of the amino acid. It is always attached to the amino group, the carboxyl group,
the side chain, and a single hydrogen. It is part of the backbone of the amino acid and is
found in every amino acid.
Given the following amino acid structure, what is the strongest intermolecular force it
would participate in to stabilize a protein structure?
Ionic bond
Disulfide bond
Hydrogen bond
Hydrophobic interaction - Answers -Hydrophobic interaction
The amino acid pictured only has CH groups in its side chain, and therefore is non-
polar. Non-polar amino acids make hydrophobic interactions.
Which change would most likely result in a permanent modification of an expressed
protein's function?
An increase in the pH of a solution in which a protein is dissolved from 6.5 to 8.0, when
it is known that the protein has an optimal activity of pH 7.8
A mutation of the gene for a protein that leads to the substitution of a hydrophobic
amino acid with a nonpolar amino acid
A mutation of the gene for a protein that leads to the substitution of a nonpolar amino
acid with a charged amino acid
The mutation of a gene for an enzyme involved in protein synthesis following exposure
to X-rays, causing the protein not to be synthesized - Answers -A mutation of the gene
for a protein that leads to the substitution of a nonpolar amino acid with a charged
amino acid.
, The mutation of nonpolar amino acid to a charged amino acid will disrupt the original
hydrophobic interaction, permanently changing the function of the protein.
Which property of enzymes is illustrated in the final step of the enzymatic cycle?
Enzymes are specific.
Enzymes increase the reaction rate for a reaction.
Enzymes are reusable.
Enzymes lower the activation energy for a reaction. - Answers -Enzymes are reusable.
In the final step of the enzymatic cycle, the product is released and the enzyme is able
to bind to a new substrate and begin the cycle again.
In the enzyme cycle, which step immediately follows induced fit?
Formation of the enzyme-substrate complex
Release of the product and enzyme complex
Formation of the enzyme-molecule complex
Formation of the enzyme-product complex - Answers -Formation of the enzyme-product
complex
The induced fit refers to the conformational change that the enzyme undergoes when it
binds to the substrate to form the enzyme-substrate complex. Therefore, the enzymatic
cycle step that occurs after the induced fit is the formation of the enzyme-product
complex.
Which type of inhibition occurs when a particular drug binds to the active site of an
enzyme?
Competitive
Uncompetitive
Irreversible
Noncompetitive - Answers -Competitive
Competitive inhibitors compete with the substrate to bind to the active site of the
enzyme.
