CH 373 Final Exam
The interactions that are the basis of molecular recognition in biological systems have the following
common characteristics: - correct answer ✔✔weak, non-covalent, reversible, and specific.
The electrostatic interaction between two ions bearing single opposite charges separated by 3 Å in water
has an energy of −5.8 kJ/mol.
What would be the energy of the same interaction if the same two ions separated by 3 Å were placed in
vacuum? - correct answer ✔✔-464 kj/mol
Van der Waal energy term describes ______attractions and ______ repulsions between atoms - correct
answer ✔✔Weak-strong
The amino acids in any eukaryotic protein have which of the following configurations?
D,R,L,S - correct answer ✔✔S
Which of the following statements regarding peptide bonds is least accurate
A
Peptide bonds tend to form a planar structure.
B
Peptide bonds are thermodynamically unstable, but kinetically stable.
C
Favored conformation of peptide bonds is with the sequential alpha carbons in the cis position.
D
Water is released during the formation of peptide bonds.
E
At equilibrium, the peptide-bond-forming reaction favors hydrolysis. - correct answer ✔✔C
,The dominant interaction that drives a water-soluble protein to fold is:
A
H-bonding
B
formation of strong, covalent bonds
C
the hydrophobic effect
D
all the weak, and weakly directional interactions
E
charged and polar residues on the outside, in contact with the water - correct answer ✔✔C
The glucocorticoid receptor is a protein that plays a key role in the body's inflammation response. The
drug hydrocortisone binds this protein with a Kd = 20 nM, and the drug dexamethasone binds it with a
Kd = 2 nM. Which of the following statements is true?
A
Dexamethasone has a lower Kd and binds with higher affinity
B
Hydrocortisone has a higher Kd and binds with higher affinity
C
The glucocorticoid receptor will have Y = 0.5 when [hydrocortisone] = [dexamethasone] - correct answer
✔✔A
Given the structures of Myoglobin and Hemoglobin molecules below , myoglobin and the subunits of
hemoglobin have:
answerable question reference
A
no obvious structural relationship
B
very different primary and tertiary structures
, C
very similar primary and tertiary structures
D
very similar primary structures, but different tertiary structures
E
very similar tertiary structures, but different primary structures - correct answer ✔✔E
In the binding of oxygen to myoglobin, the relationship between the concentration of oxygen and the
fraction of binding sites occupied can best be described as:
A
Hyperbolic
B
Linear with a negative slope
C
Linear with a positive slope
D
Sigmoidal - correct answer ✔✔A
In a mixture of the five proteins listed below, which should elute second in size-exclusion (gel filtration)
chromatography?
A
cytochrome c Mr = 13,000
B
immunoglobulin G Mr = 145,000
C
ribonuclease A Mr = 13,700
D
RNA polymerase Mr = 450,000
E
The interactions that are the basis of molecular recognition in biological systems have the following
common characteristics: - correct answer ✔✔weak, non-covalent, reversible, and specific.
The electrostatic interaction between two ions bearing single opposite charges separated by 3 Å in water
has an energy of −5.8 kJ/mol.
What would be the energy of the same interaction if the same two ions separated by 3 Å were placed in
vacuum? - correct answer ✔✔-464 kj/mol
Van der Waal energy term describes ______attractions and ______ repulsions between atoms - correct
answer ✔✔Weak-strong
The amino acids in any eukaryotic protein have which of the following configurations?
D,R,L,S - correct answer ✔✔S
Which of the following statements regarding peptide bonds is least accurate
A
Peptide bonds tend to form a planar structure.
B
Peptide bonds are thermodynamically unstable, but kinetically stable.
C
Favored conformation of peptide bonds is with the sequential alpha carbons in the cis position.
D
Water is released during the formation of peptide bonds.
E
At equilibrium, the peptide-bond-forming reaction favors hydrolysis. - correct answer ✔✔C
,The dominant interaction that drives a water-soluble protein to fold is:
A
H-bonding
B
formation of strong, covalent bonds
C
the hydrophobic effect
D
all the weak, and weakly directional interactions
E
charged and polar residues on the outside, in contact with the water - correct answer ✔✔C
The glucocorticoid receptor is a protein that plays a key role in the body's inflammation response. The
drug hydrocortisone binds this protein with a Kd = 20 nM, and the drug dexamethasone binds it with a
Kd = 2 nM. Which of the following statements is true?
A
Dexamethasone has a lower Kd and binds with higher affinity
B
Hydrocortisone has a higher Kd and binds with higher affinity
C
The glucocorticoid receptor will have Y = 0.5 when [hydrocortisone] = [dexamethasone] - correct answer
✔✔A
Given the structures of Myoglobin and Hemoglobin molecules below , myoglobin and the subunits of
hemoglobin have:
answerable question reference
A
no obvious structural relationship
B
very different primary and tertiary structures
, C
very similar primary and tertiary structures
D
very similar primary structures, but different tertiary structures
E
very similar tertiary structures, but different primary structures - correct answer ✔✔E
In the binding of oxygen to myoglobin, the relationship between the concentration of oxygen and the
fraction of binding sites occupied can best be described as:
A
Hyperbolic
B
Linear with a negative slope
C
Linear with a positive slope
D
Sigmoidal - correct answer ✔✔A
In a mixture of the five proteins listed below, which should elute second in size-exclusion (gel filtration)
chromatography?
A
cytochrome c Mr = 13,000
B
immunoglobulin G Mr = 145,000
C
ribonuclease A Mr = 13,700
D
RNA polymerase Mr = 450,000
E
