BCH 403 Final Exam Questions Solved 100%
Correct | Latest Update
You've discovered a new species of rodent living at a very high altitude, where the
partial pressure of oxygen is low. What would you predict regarding the oxygen-binding
capacity of this new species? - Answer It's hemoglobin will have a very low P50 value
AND The primary amino acid sequence of its hemoglobin will not be identical to that of
a species living in an oxygen-rich atmosphere
The following peptide is composed of which amino acid sequence - Answer
LKQIFKDIWTIGW
The following sequence of 16 residues represents an alpha helical stretch in an enzyme
from the bacterium that causes tuberculosis. Which of the following is NOT TURE
regarding the structure of this alpha helix
QFLRDTANSLLDNLIT - Answer Mutation of they phenylalanine residue to a proline will
prevent the rest of the sequence from forming an alpha helix
The residue sequence of a fibrous protein is show below. Which protein does it most
likely correspond to?
MGISQKLYRDVNNAFQSRINYWLS - Answer Fibroin
Which of the following is true regarding oxygen binding to one molecule of myoglobin -
Answer A histidine is required to hydrogen-bond with the bound oxygen, thus stabilizing
it AND the iron atom is located outside the plane of the heme when oxygen is not bound
,A chromatography column was used to try to purify a protein that is 10 kDa in size.
Some of the elution fractions were run on SDS-PAGE and are shown blow ,with lower
numbered fractions eluting first. Based on this information, what kind of
chromatographic column was used and was this attempt successful? The charges on the
gel are shown on the left - Answer Gel filtration, and it did work
Your goal is to separate a mixture of the two polypeptides shown below, and obtain a
purified peptide 1 for further study as a neurotransmitter. Which purification technique
would be most effective and why?
Peptide 1: MHTRRAPLQAWKKPRADHVL
Peptide 2:
MHTDEAPLQAWKDPEADHVLW - Answer Cation exchange, since peptide 1 is more
positively charged and will "stick" to that resin best
Ascorbate (Vitamin C) is an important part of any diet because - Answer It is required by
enzymes that hydroxylate lysine and proline, which allows these side chains to
participate in stabilizing hydrogen bonds b/t strands of tropocollagen
Why do proteins fold - Answer It is entropically favorable for water AND it is
enthalpically favorable for the protein
The structural changes in hemoglobin that contribute toward its positive cooperativity
for oxygen consist of - Answer the movement of iron into the plane of the heme AND
movement of neighboring valine residue due to strain from changes in the heme
The following oxygen binding curves are derived from independent experiments. Which
of the following statements is NOT true regarding these plots - Answer When comparing
3 with 4, curve 4 is less likely to be bound to BPG
, What is the molecular basis for sickle cell anemia - Answer A polar residue in
hemoglobin is mutated to valine, a non-polar residue, causing the protein to aggregate
into fibers
Which of the following tripeptides will bind to an anion exchange column at pH 7?
Peptide A: Glu-Lys-Arg
Peptide B: Glu-Asp-Arg - Answer peptide B will bind
Which of the following is true regarding Michaelis-Menten enzyme kinematics - Answer
The Michaelis constant (Km) is the substrate concentration when the velocity is one half
of maximum AND
At infinite substrate concentration, the reaction becomes zero order with respect to
substrate
In an enzyme catalyzed reaction, delta delta G double dagger (change in the free energy
of activation) is found to be very small when compared to the net free energy of
activation. Which of the following are also true of this reaction - Answer The velocity will
increase slightly
The "steady state" in enzyme kinematics refers to a point in the rxn when the
concentration of the ES complex is not dramatically increasing or decreasing - Answer
True
Acid-base catalysis involving free protons or hydroxide ions is thermodynamically
favorable b/c these are already in high concentrations in the cell - Answer false
Based on the data presented in question 14, the effect of that inhibitor can also be
described using the following lineweaver-Burk plot - Answer false
Correct | Latest Update
You've discovered a new species of rodent living at a very high altitude, where the
partial pressure of oxygen is low. What would you predict regarding the oxygen-binding
capacity of this new species? - Answer It's hemoglobin will have a very low P50 value
AND The primary amino acid sequence of its hemoglobin will not be identical to that of
a species living in an oxygen-rich atmosphere
The following peptide is composed of which amino acid sequence - Answer
LKQIFKDIWTIGW
The following sequence of 16 residues represents an alpha helical stretch in an enzyme
from the bacterium that causes tuberculosis. Which of the following is NOT TURE
regarding the structure of this alpha helix
QFLRDTANSLLDNLIT - Answer Mutation of they phenylalanine residue to a proline will
prevent the rest of the sequence from forming an alpha helix
The residue sequence of a fibrous protein is show below. Which protein does it most
likely correspond to?
MGISQKLYRDVNNAFQSRINYWLS - Answer Fibroin
Which of the following is true regarding oxygen binding to one molecule of myoglobin -
Answer A histidine is required to hydrogen-bond with the bound oxygen, thus stabilizing
it AND the iron atom is located outside the plane of the heme when oxygen is not bound
,A chromatography column was used to try to purify a protein that is 10 kDa in size.
Some of the elution fractions were run on SDS-PAGE and are shown blow ,with lower
numbered fractions eluting first. Based on this information, what kind of
chromatographic column was used and was this attempt successful? The charges on the
gel are shown on the left - Answer Gel filtration, and it did work
Your goal is to separate a mixture of the two polypeptides shown below, and obtain a
purified peptide 1 for further study as a neurotransmitter. Which purification technique
would be most effective and why?
Peptide 1: MHTRRAPLQAWKKPRADHVL
Peptide 2:
MHTDEAPLQAWKDPEADHVLW - Answer Cation exchange, since peptide 1 is more
positively charged and will "stick" to that resin best
Ascorbate (Vitamin C) is an important part of any diet because - Answer It is required by
enzymes that hydroxylate lysine and proline, which allows these side chains to
participate in stabilizing hydrogen bonds b/t strands of tropocollagen
Why do proteins fold - Answer It is entropically favorable for water AND it is
enthalpically favorable for the protein
The structural changes in hemoglobin that contribute toward its positive cooperativity
for oxygen consist of - Answer the movement of iron into the plane of the heme AND
movement of neighboring valine residue due to strain from changes in the heme
The following oxygen binding curves are derived from independent experiments. Which
of the following statements is NOT true regarding these plots - Answer When comparing
3 with 4, curve 4 is less likely to be bound to BPG
, What is the molecular basis for sickle cell anemia - Answer A polar residue in
hemoglobin is mutated to valine, a non-polar residue, causing the protein to aggregate
into fibers
Which of the following tripeptides will bind to an anion exchange column at pH 7?
Peptide A: Glu-Lys-Arg
Peptide B: Glu-Asp-Arg - Answer peptide B will bind
Which of the following is true regarding Michaelis-Menten enzyme kinematics - Answer
The Michaelis constant (Km) is the substrate concentration when the velocity is one half
of maximum AND
At infinite substrate concentration, the reaction becomes zero order with respect to
substrate
In an enzyme catalyzed reaction, delta delta G double dagger (change in the free energy
of activation) is found to be very small when compared to the net free energy of
activation. Which of the following are also true of this reaction - Answer The velocity will
increase slightly
The "steady state" in enzyme kinematics refers to a point in the rxn when the
concentration of the ES complex is not dramatically increasing or decreasing - Answer
True
Acid-base catalysis involving free protons or hydroxide ions is thermodynamically
favorable b/c these are already in high concentrations in the cell - Answer false
Based on the data presented in question 14, the effect of that inhibitor can also be
described using the following lineweaver-Burk plot - Answer false
