Question 1

What is the type of symmetry that relates the protomers in hemoglobin with respect to each other?

Accepted Answer

A)  C2
B)  C4
C)  D2
D)  D4
E)  Tetrahedral symmetry

Question 2

When the partial pressure of O2 in venous blood is 30 torr, the saturation of myoglobin with O2 is ______ while the saturation of hemoglobin with O2 is ______.

Accepted Answer

A)  0.55, 0.91
B)  0.91, 0.55
C)  2.8 torr, 26 torr
D)  0.91, 0.97
E)  none of the above

Question 3

IgG is the most common immunoglobulin in the circulatory system and in the extravascular fluid.It is composed of two light chains and two heavy chains.What is the approximate molecular mass of an IgG molecule?

Accepted Answer

A)  23 kDa
B)  75 kDa
C)  150 kDa
D)  360 kDa
E)  950 kDa

Question 4

Matching
-The conversion of hemoglobin from the T to the R state requires breaking of ______ involving C-terminal residues.

Accepted Answer

A)  positively cooperative
B)  cyanosis
C)  His E7
D)  decrease
E)  RF) hydrogen bondsG) increaseH) symmetryI) His F8J) ion pairsK) TL) hemolytic anemiaM) sequencial

Question 5

Matching
-Sickle cell hemoglobin does not form fibers in the ______ form.

Accepted Answer

A)  positively cooperative
B)  cyanosis
C)  His E7
D)  decrease
E)  RF) hydrogen bondsG) increaseH) symmetryI) His F8J) ion pairsK) TL) hemolytic anemiaM) sequencial E

Question 6

Myoglobin and a single chain of hemoglobin have similar ______ structures.

Accepted Answer

A)  primary
B)  secondary
C)  tertiary
D)  quaternary
E)  none of the above C

Question 7

Matching
-An increase in pCO2 causes hemoglobin's affinity for oxygen to ______.

Accepted Answer

A)  positively cooperative
B)  cyanosis
C)  His E7
D)  decrease
E)  RF) hydrogen bondsG) increaseH) symmetryI) His F8J) ion pairsK) TL) hemolytic anemiaM) sequencial

Question 8

Humoral immunity is mediated by soluble molecules.Which cell type produces the soluble molecules that carry out the humoral immunity?

Accepted Answer

A)  T cells
B)  B cells
C)  macrophages
D)  neutrophils
E)  monocytes

Question 9

Which of the following statements about the symmetry model of allosterism is not true?

Accepted Answer

A)  the protein is an oligomer of symmetrically (or pseudosymmetrically) related subunits.
B)  the oligomer can exist in two conformational states, which are in equilibrium.
C)  the ligand can bind to a subunit in either conformation.
D)  the molecular symmetry of the protein is conserved during the conformational change.
E)  none of the above.

Question 10

During muscle contraction

Accepted Answer

A)  myosin pulls actin filaments toward the M disk.
B)  myosin pushes actin filaments toward the Z disk.
C)  actin pulls myosin toward the Z disk.
D)  actin pushes myosin toward the M disk.
E)  All of the answers above are correct.

Question 11

Why is the decreased affinity of fetal hemoglobin for BPG advantageous?

Accepted Answer

A)  With fewer BPG molecules bound there are more heme residues available for O2 binding.
B)  Decreased BPG binding biases the fetal hemoglobin toward the R state.
C)  More free BPG is available to bind to adult hemoglobin, resulting in a shift to the R state.
D)  BPG is available to bind to fetal myoglobin, helping to release O2 in fetal muscle tissue.
E)  none of the above

Question 12

Hemoglobin S, the variant responsible for the misshapen red blood cells characteristic of the disease sickle-cell anemia, is potentially advantageous to heterozygotes because it confers some level of resistance to the disease _________.

Accepted Answer

A)  rickets
B)  AIDS
C)  cyanosis
D)  polycythemia
E)  malaria

Question 13

BPG stands for

Accepted Answer

A)  biphenylglycine.
B)  boronylphenylglutamate.
C)  bisphosphoglycerate.
D)  bisphenylglycerol.
E)  betapropylglutamine.

Question 14

The reaction of carbonic anhydrase catalyzes

Accepted Answer

A)  the formation of carbamates with the concomitant release of protons.
B)  the hydration of bicarbonate, resulting in the formation of carbonic acid.
C)  the reduction of carbon dioxide with the concomitant consumption of protons.
D)  the hydration of carbon dioxide, forming bicarbonate and protons.
E)  the hydrolysis of carbamates with the concomitant consumption of protons. D

Question 15

The Ig fold can be described as a

Accepted Answer

A)  globular fold composed of  α\alphaα  helices.
B)  a globular fold composed of a four helix bundle.
C)  a globular fold composed of a  β\betaβ  sandwich.
D)  a globular fold composed of  β\betaβ  barrel.
E)  a coiled-coil.

Question 16

Which statement about myosin is not true?

Accepted Answer

A)  Myosin is a heterohexamer.
B)  Myosin contains two globular heads.
C)  Myosin contains six different polypeptides
D)  Myosin aggregates to form thick filaments
E)  All of the answers above are true of myosin.

Question 17

Treadmilling refers to

Accepted Answer

A)  myosin heads walking along actin microfilaments.
B)  actin and myosin filaments sliding along each other.
C)  actin monomers moving through a microfilament from the + end to the - end.
D)  synthesis and degradation of actin monomers.
E)  the interactions between actin and tropomyosin.

Question 18

Myoglobin is an oxygen binding protein in muscle.Describe in one sentence the overall structure of myoglobin.

Accepted Answer

Myoglobin is a globular protei...

Question 19

Matching
-In the ______ state of hemoglobin, the iron ion is out of the plane of the porphyrin ring.

Accepted Answer

A)  positively cooperative
B)  cyanosis
C)  His E7
D)  decrease
E)  RF) hydrogen bondsG) increaseH) symmetryI) His F8J) ion pairsK) TL) hemolytic anemiaM) sequencial

Question 20

IgG is one of five classes of antibodies that can be produced by our immune system.IgGs have a molecular mass of approximately 150 kDa, what is their subunit composition?

Accepted Answer

A)  2 light chains and 2 heavy chains
B)  2 light chains, 2 heavy chains, and a J chain
C)  4 light chains, 4 heavy chains, and a J chain
D)  6 light chains, 6 heavy chains, and a J chain
E)  10 light chains, 10 heavy chains , and a J chain.

Exam 7: Protein Function Part I: Myoglobin and Hemoglobin

What is the type of symmetry that relates the protomers in hemoglobin with respect to each other?

Correct AnswerverifiedShow Answer

When the partial pressure of O2 in venous blood is 30 torr, the saturation of myoglobin with O2 is ______ while the saturation of hemoglobin with O2 is ______.

Correct AnswerverifiedShow Answer

IgG is the most common immunoglobulin in the circulatory system and in the extravascular fluid.It is composed of two light chains and two heavy chains.What is the approximate molecular mass of an IgG molecule?

Correct AnswerverifiedShow Answer

Matching -The conversion of hemoglobin from the T to the R state requires breaking of ______ involving C-terminal residues.

Correct AnswerverifiedShow Answer

Matching -Sickle cell hemoglobin does not form fibers in the ______ form.

Correct AnswerverifiedE

Myoglobin and a single chain of hemoglobin have similar ______ structures.

Correct AnswerverifiedC

Matching -An increase in pCO2 causes hemoglobin's affinity for oxygen to ______.

Correct AnswerverifiedShow Answer

Humoral immunity is mediated by soluble molecules.Which cell type produces the soluble molecules that carry out the humoral immunity?

Correct AnswerverifiedShow Answer

Which of the following statements about the symmetry model of allosterism is not true?

Correct AnswerverifiedShow Answer

During muscle contraction

Correct AnswerverifiedShow Answer

Why is the decreased affinity of fetal hemoglobin for BPG advantageous?

Correct AnswerverifiedShow Answer

Hemoglobin S, the variant responsible for the misshapen red blood cells characteristic of the disease sickle-cell anemia, is potentially advantageous to heterozygotes because it confers some level of resistance to the disease _________.

Correct AnswerverifiedShow Answer

BPG stands for

Correct AnswerverifiedShow Answer

The reaction of carbonic anhydrase catalyzes

Correct AnswerverifiedD

The Ig fold can be described as a

Correct AnswerverifiedShow Answer

Which statement about myosin is not true?

Correct AnswerverifiedShow Answer

Treadmilling refers to

Correct AnswerverifiedShow Answer

Myoglobin is an oxygen binding protein in muscle.Describe in one sentence the overall structure of myoglobin.

Correct AnswerverifiedMyoglobin is a globular protei...View AnswerShow Answer

Matching -In the ______ state of hemoglobin, the iron ion is out of the plane of the porphyrin ring.

Correct AnswerverifiedShow Answer

IgG is one of five classes of antibodies that can be produced by our immune system.IgGs have a molecular mass of approximately 150 kDa, what is their subunit composition?

Correct AnswerverifiedShow Answer

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When the partial pressure of O₂ in venous blood is 30 torr, the saturation of myoglobin with O₂ is while the saturation of hemoglobin with O₂ is .

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E

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C

Matching -An increase in pCO₂ causes hemoglobin's affinity for oxygen to ______.

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D

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Myoglobin is a globular protei...
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