BCH403 FINAL PREPARATION
EXAM QUESTIONS WITH
COMPLETE SOLUTIONS
Which of the following pairs of amino acids are polar, but uncharged at neutral pH: -
Answer-N, Q
Which of the following is NOT TRUE regarding a biochemical reaction? - Answer-A
largely negative delta G means that eventually, the reactants will run out completely.
Which of the following is NOT part of the peptide bond plane? - Answer-R-group of the
second residue
Secondary structures are stabilized by which of the following? - Answer-Hydrogen-
bonding between a carbonyl oxygen and an amide hydrogen
In Myoglobin, the bound oxygen occupies the sixth ligand for iron, meaning that no
more than one molecule of oxygen can bind per molecule of protein - Answer-True
Interior packing of hydrophobic residues contributes favorably to both delta S and delta
H because of the hydrophobic effect and the many hydrogen-bonding interactions
between nonpolar side chains - Answer-False
The following amino acid sequence belongs to a fibrous protein.
GAAGPPGPAGPAGERGEQGAPGPSGFQGLPGPP. Which of the following is the best
match? - Answer-Tropocollagen
The following is the secondary structure of a polypeptide. The cylinders represent
amphipathic alpha helices. Which of the following primary sequences would most
closely match the structure? - Answer-
GMADRLLNEPRISSAIVASAAQWVSTIVKFAMKISAVIPR
Affinity chromatography: - Answer-separates proteins based on attraction to another
molecule
Covalent cross-linking of lysine side chains is a feature that helps stabilize: - Answer-
Tropocollagen
Peptide bonds behave as rigid planes because of the partial double-bond character
between the carbonyl carbon of one residue and the amide hydrogen of another residue
- Answer-False
, The diagonal contacts between the alpha-1 and the beta-2 subunits of Hb are important
for cooperativity because of: - Answer-They are intermediate strength, so that they can
move, but a change in one causes a change in the other.
Which amino acid is most likely to stabilize extracellular proteins and why? - Answer-
cysteine because it forms covalent disulfide bonds
In Michaelis-Menten enzyme kinetics, when an enzyme becomes halfway saturated with
substrate, the reaction becomes zero order with respect to substrate - Answer-False
The strong electronegativity of carbon is responsible for the lack of hydrogen bonding
for molecules that contain hydrocarbons - Answer-False
You intend to determine the structure of a small protein that folds into multiple
conformations. Which of the following strategies is most appropriate? - Answer-Nuclear
Magnetic Resonance
The Henderson-Hasselbach equation is only able to calculate the fraction ionization of
an amino acid when the pH is equal to the pKa - Answer-False
The basis of cooperativity in hemoglobin requires that the heme plane becomes
flattened upon oxygen binding, which is followed by a change in the protein
conformation - Answer-True
A vitamin-C deficiency causes the disease known as Scurvy because the enzyme lysyl
oxidase becomes non-functional - Answer-False
The classic unfolding experiment using Ribonuclease A demonstrated that: - Answer-
The information needed to fold a protein is encoded in the primary amino acid
sequence.
The transient force which, while weak, still has a large impact on how protein molecules
fold is the - Answer-Van der Waals interaction
You've modified Myoglobin to make two mutants. Mutant X replaces the proximal
histidine with an alanine. Mutant Y replaces the distal histidine with an alanine. Which of
the following saturation curves best match the different forms of Mb? - Answer-
Unmodified Mb: 1
Mutant X: 4
Mutant Y: 2
Dr. Estrada really loves histidine. You might even say that he's obsessed. What feature
of this amino acid allows it to serve as both a proton acceptor as well as a proton donor
at a neutral pH? - Answer-The side chain of histidine can be protonated, in which case it
becomes positively charged.
EXAM QUESTIONS WITH
COMPLETE SOLUTIONS
Which of the following pairs of amino acids are polar, but uncharged at neutral pH: -
Answer-N, Q
Which of the following is NOT TRUE regarding a biochemical reaction? - Answer-A
largely negative delta G means that eventually, the reactants will run out completely.
Which of the following is NOT part of the peptide bond plane? - Answer-R-group of the
second residue
Secondary structures are stabilized by which of the following? - Answer-Hydrogen-
bonding between a carbonyl oxygen and an amide hydrogen
In Myoglobin, the bound oxygen occupies the sixth ligand for iron, meaning that no
more than one molecule of oxygen can bind per molecule of protein - Answer-True
Interior packing of hydrophobic residues contributes favorably to both delta S and delta
H because of the hydrophobic effect and the many hydrogen-bonding interactions
between nonpolar side chains - Answer-False
The following amino acid sequence belongs to a fibrous protein.
GAAGPPGPAGPAGERGEQGAPGPSGFQGLPGPP. Which of the following is the best
match? - Answer-Tropocollagen
The following is the secondary structure of a polypeptide. The cylinders represent
amphipathic alpha helices. Which of the following primary sequences would most
closely match the structure? - Answer-
GMADRLLNEPRISSAIVASAAQWVSTIVKFAMKISAVIPR
Affinity chromatography: - Answer-separates proteins based on attraction to another
molecule
Covalent cross-linking of lysine side chains is a feature that helps stabilize: - Answer-
Tropocollagen
Peptide bonds behave as rigid planes because of the partial double-bond character
between the carbonyl carbon of one residue and the amide hydrogen of another residue
- Answer-False
, The diagonal contacts between the alpha-1 and the beta-2 subunits of Hb are important
for cooperativity because of: - Answer-They are intermediate strength, so that they can
move, but a change in one causes a change in the other.
Which amino acid is most likely to stabilize extracellular proteins and why? - Answer-
cysteine because it forms covalent disulfide bonds
In Michaelis-Menten enzyme kinetics, when an enzyme becomes halfway saturated with
substrate, the reaction becomes zero order with respect to substrate - Answer-False
The strong electronegativity of carbon is responsible for the lack of hydrogen bonding
for molecules that contain hydrocarbons - Answer-False
You intend to determine the structure of a small protein that folds into multiple
conformations. Which of the following strategies is most appropriate? - Answer-Nuclear
Magnetic Resonance
The Henderson-Hasselbach equation is only able to calculate the fraction ionization of
an amino acid when the pH is equal to the pKa - Answer-False
The basis of cooperativity in hemoglobin requires that the heme plane becomes
flattened upon oxygen binding, which is followed by a change in the protein
conformation - Answer-True
A vitamin-C deficiency causes the disease known as Scurvy because the enzyme lysyl
oxidase becomes non-functional - Answer-False
The classic unfolding experiment using Ribonuclease A demonstrated that: - Answer-
The information needed to fold a protein is encoded in the primary amino acid
sequence.
The transient force which, while weak, still has a large impact on how protein molecules
fold is the - Answer-Van der Waals interaction
You've modified Myoglobin to make two mutants. Mutant X replaces the proximal
histidine with an alanine. Mutant Y replaces the distal histidine with an alanine. Which of
the following saturation curves best match the different forms of Mb? - Answer-
Unmodified Mb: 1
Mutant X: 4
Mutant Y: 2
Dr. Estrada really loves histidine. You might even say that he's obsessed. What feature
of this amino acid allows it to serve as both a proton acceptor as well as a proton donor
at a neutral pH? - Answer-The side chain of histidine can be protonated, in which case it
becomes positively charged.
