BIOC 384 Exam 2 Questions & Answers,
Well Elaborated | Already Verified Test
|100% Verified solutions | Latest UPDATE
2026
Consider the following interaction between a protein and its : [P] + [L] mc021-1.jpg [PL].
If [L] = 5 mM, [P] = 3 mM, and [PL] = 2 mM, what is the dissociation constant? -
CORRECTANSWER 7.5 mM
Which of the TWO following statements about x-ray crystallography are true? -
CORRECTANSWER Only crystallized proteins can be analyzed.
The x-ray beam is scattered by the protein sample.
A purified protein shows a single band on a native polyacrylamide gel. The band runs
toward the cathode at pH 7. The figure above shows how the same purified protein runs
on an SDS polyacrylamide gel, with or without dithiothreitol (DTT) added to the sample.
A marker lane is included with sizes of MW standards shown in kDa.
Select the TRUE CORRECTANSWERs from the statements below. -
CORRECTANSWER The protein is a heterooligomeric complex of three different
polypeptide chains.
The protein probably has a high pI value (>7).
Two subunits of the protein are linked by a disulfide bond.
,Which of the following is a genomic caretaker protein? -CORRECTANSWER
topoisomerase
Which of the following steps happens first in the oxygen binding process? -
CORRECTANSWER The O2 binds to the iron of heme.
Though oxygen only binds to a particular place in the hemoglobin molecule, the oxy-
and deoxy- forms of hemoglobin differ in overall protein conformation. An example of a
structural change that does NOT play a role in translating local binding of oxygen to
global protein conformational change would be the different ______ in the presence and
absence of oxygen binding. -CORRECTANSWER location of the distal histidine
The figure below shows the oxygen binding curve for myoglobin in muscle.
Based on this curve, which of the following is correct? -CORRECTANSWER The lower
pO2 in active muscle leads to release of O2 from myoglobin.
Consider five proteins with the properties shown in the table above and
CORRECTANSWER the following four questions. Record your CORRECTANSWERs
and choose the set of correct CORRECTANSWERs for questions a --> d.
a) Which protein would elute first from a (+) charged anion exchange column in buffer at
pH 4.0?
b) Which protein would migrate the slowest in an SDS-PAGE gel?
, c) Which protein would elute last from a gel filtration chromatography column under
non-denaturing conditions?
d) Which protein would elute last from a (-) charged cation exchange column in buffer at
pH 4.0? -CORRECTANSWER A, E, C, A
In isoelectric focusing, a protein that is physically located in the pH gradient that is
below the pI of the protein would: -CORRECTANSWER migrate toward the cathode
After centrifugation, there is a 10% decrease in activity and a 75% decrease in total
protein. What is purification of the target protein? -CORRECTANSWER 3.6-fold
One of the most difficult steps in X-ray crystallography is: -CORRECTANSWER
determining the phases of diffracted x-rays
Biochemical assays are important in the process of isolating proteins because they: -
CORRECTANSWER uniquely identify one protein
Below is a fractional saturation curve for O2 binding to adult hemoglobin. Assume that
curve Y represents a system at pH 7.4 and with a normal physiological level of 2,3-
BPG. Curve X represents a system that: -CORRECTANSWER has a higher pH with a
normal physiological level of 2,3-BPG
Well Elaborated | Already Verified Test
|100% Verified solutions | Latest UPDATE
2026
Consider the following interaction between a protein and its : [P] + [L] mc021-1.jpg [PL].
If [L] = 5 mM, [P] = 3 mM, and [PL] = 2 mM, what is the dissociation constant? -
CORRECTANSWER 7.5 mM
Which of the TWO following statements about x-ray crystallography are true? -
CORRECTANSWER Only crystallized proteins can be analyzed.
The x-ray beam is scattered by the protein sample.
A purified protein shows a single band on a native polyacrylamide gel. The band runs
toward the cathode at pH 7. The figure above shows how the same purified protein runs
on an SDS polyacrylamide gel, with or without dithiothreitol (DTT) added to the sample.
A marker lane is included with sizes of MW standards shown in kDa.
Select the TRUE CORRECTANSWERs from the statements below. -
CORRECTANSWER The protein is a heterooligomeric complex of three different
polypeptide chains.
The protein probably has a high pI value (>7).
Two subunits of the protein are linked by a disulfide bond.
,Which of the following is a genomic caretaker protein? -CORRECTANSWER
topoisomerase
Which of the following steps happens first in the oxygen binding process? -
CORRECTANSWER The O2 binds to the iron of heme.
Though oxygen only binds to a particular place in the hemoglobin molecule, the oxy-
and deoxy- forms of hemoglobin differ in overall protein conformation. An example of a
structural change that does NOT play a role in translating local binding of oxygen to
global protein conformational change would be the different ______ in the presence and
absence of oxygen binding. -CORRECTANSWER location of the distal histidine
The figure below shows the oxygen binding curve for myoglobin in muscle.
Based on this curve, which of the following is correct? -CORRECTANSWER The lower
pO2 in active muscle leads to release of O2 from myoglobin.
Consider five proteins with the properties shown in the table above and
CORRECTANSWER the following four questions. Record your CORRECTANSWERs
and choose the set of correct CORRECTANSWERs for questions a --> d.
a) Which protein would elute first from a (+) charged anion exchange column in buffer at
pH 4.0?
b) Which protein would migrate the slowest in an SDS-PAGE gel?
, c) Which protein would elute last from a gel filtration chromatography column under
non-denaturing conditions?
d) Which protein would elute last from a (-) charged cation exchange column in buffer at
pH 4.0? -CORRECTANSWER A, E, C, A
In isoelectric focusing, a protein that is physically located in the pH gradient that is
below the pI of the protein would: -CORRECTANSWER migrate toward the cathode
After centrifugation, there is a 10% decrease in activity and a 75% decrease in total
protein. What is purification of the target protein? -CORRECTANSWER 3.6-fold
One of the most difficult steps in X-ray crystallography is: -CORRECTANSWER
determining the phases of diffracted x-rays
Biochemical assays are important in the process of isolating proteins because they: -
CORRECTANSWER uniquely identify one protein
Below is a fractional saturation curve for O2 binding to adult hemoglobin. Assume that
curve Y represents a system at pH 7.4 and with a normal physiological level of 2,3-
BPG. Curve X represents a system that: -CORRECTANSWER has a higher pH with a
normal physiological level of 2,3-BPG
