Biochemistry final exam 2024/2025(detailed
questions and answers)/latest update
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-haemoglobin 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 anaemia. The structures of glutamate and valine are
shown below.
If the beta haemoglobin gene in a patient with sickle-cell anaemia 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 anaemia. 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
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
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
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
Disulphide bond
Hydrogen bond
Hydrophobic interaction (CORRECT ANSWER) 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 (CORRECT
questions and answers)/latest update
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-haemoglobin 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 anaemia. The structures of glutamate and valine are
shown below.
If the beta haemoglobin gene in a patient with sickle-cell anaemia 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 anaemia. 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
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
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
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
Disulphide bond
Hydrogen bond
Hydrophobic interaction (CORRECT ANSWER) 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 (CORRECT
