1|Page
BIOC384 EXAM 2|| QUESTIONS AND 100%
CORRECT ANSWERS ALREADY GRADED A+||
LATEST AND COMPLETE UPDATE WITH
VERIFIED SOLUTIONS GUARANTEED PASS!!!
Considering the fractional saturation binding curve of hemoglobin as shown below,
as well as the definition of fractional saturation, which of the following statements
are true about hemoglobin's oxygen binding profile? - ANSWER: -At partial
pressures of oxygen of more than 12 kPa, hemoglobin is as saturated with oxygen
as it can be, indicating that in the vast majority of hemoglobin proteins, all four
oxygen binding sites are occupied.
-The sigmoidal curve is indicative of cooperative binding. NOT the hyperbolic
curve.
The anion exchange resin, DEAE, is shown here and you have three proteins each
with a different isoelectric point (pI):Protein A pI = 7.0Protein B pI = 5.0Protein C
pI = 9.0. At which pH would you need to make a buffer to allow only protein B to
bind? Protein A pI = 7.0Protein B pI = 5.0Protein C pI = 9.0 - ANSWER: pH6.0
higher than5 but not higher than 7
Lactate dehydrogenase (LDH) is a tetrameric enzyme present in the cytosol of
cells. It catalyzes the reversible reaction that converts pyruvate to lactate, and it is
highly expressed in muscle cells. LDH participates in the clearing of lactate when
it accumulates following heavy exercise. Which of the following strategies would
be most effective in purifying LDH for further enzyme assays? - ANSWER:
Purification of active enzyme requires careful consideration of isolation strategy.
Differential centrifugation would be helpful for isolating cytosolic proteins from
the rest of the cell components. Salting out is a method of concentrating the sample
and further purifying it. And column chromatography is a third separation strategy
that is able to separate samples by size. All three methods preserve protein
function.
, 2|Page
Now that you have isolated LDH enzyme from muscle cells, you perform an
activity assay to assess purity. In the muscle cell extract, your specific activity for
LDH is 2.5 units/mg protein and in your column chromatography samples it is 12
units/mg. What is the fold purification of your new LDH sample? - ANSWER: 4.8
On the 2-D gel shown in the figure below, where would a protein with a high pI
and a high mass be found? - ANSWER: C or High(for weight) to the Right for pI
Which of the following correctly describes the association of oxygen with
hemoglobin? - ANSWER: When oxygen binds to one subunit of hemoglobin, the
affinity for oxygen binding on the other three subunits increases, and the entire
molecule shifts from the T state to the R state.
The binding of oxygen in one subunit of hemoglobin is sensed by other subunits
because o - ANSWER: hydrogen bonding across four amino acids, two aspartates,
a tyrosine and an asparagine.
Which of the following best describes the role of 2,3-BPG in the delivery of
oxygen to tissues by hemoglobin (Hb)? - ANSWER: 2,3-BPG helps maintain Hb
in the deoxygenated T-state.
The figure below shows the oxygen binding curve for myoglobin in muscle. Based
on this curve, which of the following is correct? - ANSWER: The lower pO2 in
active muscle leads to release of O2 from myoglobin.
The oxygen binding profile of hemoglobin produces a
BLANK 1 curve. Since there is a higher concentration of oxygen in the lungs than
in the tissue, hemoglobin is almost fully bound to oxygen in the BLANK 2 but
releases about 60% of its oxygen in the BLANK3 . Therefore, more hemoglobin
molecules are in the BLANK4 state when in the lungs. - ANSWER: 1) Sigmoidal
BIOC384 EXAM 2|| QUESTIONS AND 100%
CORRECT ANSWERS ALREADY GRADED A+||
LATEST AND COMPLETE UPDATE WITH
VERIFIED SOLUTIONS GUARANTEED PASS!!!
Considering the fractional saturation binding curve of hemoglobin as shown below,
as well as the definition of fractional saturation, which of the following statements
are true about hemoglobin's oxygen binding profile? - ANSWER: -At partial
pressures of oxygen of more than 12 kPa, hemoglobin is as saturated with oxygen
as it can be, indicating that in the vast majority of hemoglobin proteins, all four
oxygen binding sites are occupied.
-The sigmoidal curve is indicative of cooperative binding. NOT the hyperbolic
curve.
The anion exchange resin, DEAE, is shown here and you have three proteins each
with a different isoelectric point (pI):Protein A pI = 7.0Protein B pI = 5.0Protein C
pI = 9.0. At which pH would you need to make a buffer to allow only protein B to
bind? Protein A pI = 7.0Protein B pI = 5.0Protein C pI = 9.0 - ANSWER: pH6.0
higher than5 but not higher than 7
Lactate dehydrogenase (LDH) is a tetrameric enzyme present in the cytosol of
cells. It catalyzes the reversible reaction that converts pyruvate to lactate, and it is
highly expressed in muscle cells. LDH participates in the clearing of lactate when
it accumulates following heavy exercise. Which of the following strategies would
be most effective in purifying LDH for further enzyme assays? - ANSWER:
Purification of active enzyme requires careful consideration of isolation strategy.
Differential centrifugation would be helpful for isolating cytosolic proteins from
the rest of the cell components. Salting out is a method of concentrating the sample
and further purifying it. And column chromatography is a third separation strategy
that is able to separate samples by size. All three methods preserve protein
function.
, 2|Page
Now that you have isolated LDH enzyme from muscle cells, you perform an
activity assay to assess purity. In the muscle cell extract, your specific activity for
LDH is 2.5 units/mg protein and in your column chromatography samples it is 12
units/mg. What is the fold purification of your new LDH sample? - ANSWER: 4.8
On the 2-D gel shown in the figure below, where would a protein with a high pI
and a high mass be found? - ANSWER: C or High(for weight) to the Right for pI
Which of the following correctly describes the association of oxygen with
hemoglobin? - ANSWER: When oxygen binds to one subunit of hemoglobin, the
affinity for oxygen binding on the other three subunits increases, and the entire
molecule shifts from the T state to the R state.
The binding of oxygen in one subunit of hemoglobin is sensed by other subunits
because o - ANSWER: hydrogen bonding across four amino acids, two aspartates,
a tyrosine and an asparagine.
Which of the following best describes the role of 2,3-BPG in the delivery of
oxygen to tissues by hemoglobin (Hb)? - ANSWER: 2,3-BPG helps maintain Hb
in the deoxygenated T-state.
The figure below shows the oxygen binding curve for myoglobin in muscle. Based
on this curve, which of the following is correct? - ANSWER: The lower pO2 in
active muscle leads to release of O2 from myoglobin.
The oxygen binding profile of hemoglobin produces a
BLANK 1 curve. Since there is a higher concentration of oxygen in the lungs than
in the tissue, hemoglobin is almost fully bound to oxygen in the BLANK 2 but
releases about 60% of its oxygen in the BLANK3 . Therefore, more hemoglobin
molecules are in the BLANK4 state when in the lungs. - ANSWER: 1) Sigmoidal
