Question 1

What happens when the substrate for a serine protease is denatured?

Accepted Answer

A)  It allows for non-specific cleavage 
B)  It changes the specificity for cleavage 
C)  It inhibits cleavage 
D)  It makes the serine protease an exopeptidase 
E)  It removes any requirement for a metal ion 
A)  It allows for non-specific cleavage 
B)  It changes the specificity for cleavage 
C)  It inhibits cleavage 
D)  It makes the serine protease an exopeptidase 
E)  It removes any requirement for a metal ion

Question 2

All of the following are true of the isohydric mechanism EXCEPT:

Accepted Answer

A)  it results in no change in intra-erythrocyte pH 
B)  it is responsible for accommodating 40% of the hydrogen ions generated during CO2 transport 
C)  it is linked to oxygen uptake and release 
D)  it is responsible for the chloride shift 
A)  it results in no change in intra-erythrocyte pH 
B)  it is responsible for accommodating 40% of the hydrogen ions generated during CO2 transport 
C)  it is linked to oxygen uptake and release 
D)  it is responsible for the chloride shift

Question 3

Which of the following hemoglobins normally predominates at the time of birth?

Accepted Answer

A)  alpha2,epsilon2 
B)  alpha2,gamma2 
C)  alpha2,beta2 
D)  alpha2,delta2 
A)  alpha2,epsilon2 
B)  alpha2,gamma2 
C)  alpha2,beta2 
D)  alpha2,delta2

Question 4

Laminin and fibronectin have which characteristic in common?

Accepted Answer

A)  they bind collagen 
B)  they contain three polypeptide chains 
C)  they undergo covalent modification outside of cells 
D)  they contain a cell-binding domain characterized by an RDG sequence 
A)  they bind collagen 
B)  they contain three polypeptide chains 
C)  they undergo covalent modification outside of cells 
D)  they contain a cell-binding domain characterized by an RDG sequence

Question 5

The affinity of hemoglobin for oxygen (O2) is increased by an increase in the concentration of

Accepted Answer

A)  2,3-bisphosphoglycerate. 
B)  carbon dioxide. 
C)  hydrogen ion. 
D)  nitric oxide. 
E)  oxygen. 
A)  2,3-bisphosphoglycerate. 
B)  carbon dioxide. 
C)  hydrogen ion. 
D)  nitric oxide. 
E)  oxygen.

Question 6

The part of the antigen that is recognized by the antibody is called

Accepted Answer

A)  the variable region. 
B)  the hypervariable region. 
C)  the constant region. 
D)  an epitope. 
E)  the immunoglobulin fold. 
A)  the variable region. 
B)  the hypervariable region. 
C)  the constant region. 
D)  an epitope. 
E)  the immunoglobulin fold.

Question 7

The part of the antigen that is recognized by the antibody is called

Accepted Answer

A)  the variable region. 
B)  the hypervariable region. 
C)  the constant region. 
D)  an epitope. 
E)  the immunoglobulin fold. 
A)  the variable region. 
B)  the hypervariable region. 
C)  the constant region. 
D)  an epitope. 
E)  the immunoglobulin fold.

Question 8

All of the following statements about the conversion of hemoglobin from taut to relaxed forms are correct, EXCEPT

Accepted Answer

A)  additional inter-subunit salt bridges are formed. 
B)  affinity for molecular oxygen increases. 
C)  the subunits move relative to one another. 
D)  BPG is excluded from the central cavity of the molecule. 
E)  affinity for carbon dioxide decreases. 
A)  additional inter-subunit salt bridges are formed. 
B)  affinity for molecular oxygen increases. 
C)  the subunits move relative to one another. 
D)  BPG is excluded from the central cavity of the molecule. 
E)  affinity for carbon dioxide decreases.

Question 9

What are the family of specific serine protease inhibitors called?

Accepted Answer

A)  Acrosins 
B)  Cathepsins 
C)  Kallikreins 
D)  Proteins C 
E)  Serpins 
A)  Acrosins 
B)  Cathepsins 
C)  Kallikreins 
D)  Proteins C 
E)  Serpins

Question 10

When the oxygen-saturation curve of hemoglobin is analyzed by use of the Hill equation, a Hill constant of about 3 is found. This means that

Accepted Answer

A)  only 3 of the 4 hemes can bind O2. 
B)  negative cooperativity causes hemoglobin to behave as if it had only 3 hemes that can bind O2. 
C)  each of the 4 hemes can bond O2, but not as tightly as they would in the absence of cooperativity. 
D)  the binding of O2 is highly, but not perfectly, cooperative. 
E)  3 of the heme groups bind O2 equally tightly, and the 4th heme binds O2 more tightly. 
A)  only 3 of the 4 hemes can bind O2. 
B)  negative cooperativity causes hemoglobin to behave as if it had only 3 hemes that can bind O2. 
C)  each of the 4 hemes can bond O2, but not as tightly as they would in the absence of cooperativity. 
D)  the binding of O2 is highly, but not perfectly, cooperative. 
E)  3 of the heme groups bind O2 equally tightly, and the 4th heme binds O2 more tightly.

Question 11

Which of the following statements about hemoglobin is true?

Accepted Answer

A)  BPG decreases the affinity of hemoglobin for oxygen by stabilizing the T-state 
B)  BPG decreases the affinity of hemoglobin for oxygen by releasing an H+ 
C)  hemoglobin is composed of 4 myoglobin molecules 
D)  hemoglobin binds carbon dioxide at the heme oxygen binding site 
E)  increased acidity increases hemoglobin's oxygen affinity 
A)  BPG decreases the affinity of hemoglobin for oxygen by stabilizing the T-state 
B)  BPG decreases the affinity of hemoglobin for oxygen by releasing an H+ 
C)  hemoglobin is composed of 4 myoglobin molecules 
D)  hemoglobin binds carbon dioxide at the heme oxygen binding site 
E)  increased acidity increases hemoglobin's oxygen affinity

Question 12

All of the following are true regarding IgM's EXCEPT which one?

Accepted Answer

A)  They have a short half-life. 
B)  They are the first to be synthesized after antigenic stimulation. 
C)  They cross the placenta. 
D)  They are present mainly in plasma. 
E)  They consist of several subunits. 
A)  They have a short half-life. 
B)  They are the first to be synthesized after antigenic stimulation. 
C)  They cross the placenta. 
D)  They are present mainly in plasma. 
E)  They consist of several subunits.

Question 13

Carbon monoxide is toxic because

Accepted Answer

A)  it is a negative allosteric effector and lowers the affinity of hemoglobin for oxygen. 
B)  it oxidizes Fe2+ (ferrous) to Fe3+ (ferric). 
C)  it reacts chemically with one of the essential amino acid sidechains and inactivates the hemoglobin. 
D)  it binds competitively to the heme group and thus lowers the amount of oxygen bound. 
A)  it is a negative allosteric effector and lowers the affinity of hemoglobin for oxygen. 
B)  it oxidizes Fe2+ (ferrous) to Fe3+ (ferric). 
C)  it reacts chemically with one of the essential amino acid sidechains and inactivates the hemoglobin. 
D)  it binds competitively to the heme group and thus lowers the amount of oxygen bound.

Question 14

The predominant class of antibody produced in the primary immune response is

Accepted Answer

A)  IgM 
B)  IgG 
C)  IgD 
D)  IgA 
E)  IgE 
A)  IgM 
B)  IgG 
C)  IgD 
D)  IgA 
E)  IgE

Question 15

The complementarity-determining regions of an immunoglobulin G molecule The complementarity-determining regions of an immunoglobulin G molecule

Accepted Answer

A)  are a feature of all immunoglobulin domains. 
B)  are located in the light but not the heavy chains. 
C)  participate in the covalent attachment of oligosaccharide groups. 
D)  specify interactions with antigens or epitopes. 
E)  stabilize overall protein structure. 
A)  are a feature of all immunoglobulin domains. 
B)  are located in the light but not the heavy chains. 
C)  participate in the covalent attachment of oligosaccharide groups. 
D)  specify interactions with antigens or epitopes. 
E)  stabilize overall protein structure.

Question 16

Which of the following statements about the Bohr effect is TRUE?

Accepted Answer

A)  Deoxyhemoglobin is a stronger acid than oxyhemoglobin. 
B)  The pKa for deoxyhemoglobin is less than the pKa for oxyhemoglobin. 
C)  hemoglobin oxygenation is favored in environments with a greater carbon dioxide concentration. 
D)  hemoglobin protonation favors oxygen release. 
A)  Deoxyhemoglobin is a stronger acid than oxyhemoglobin. 
B)  The pKa for deoxyhemoglobin is less than the pKa for oxyhemoglobin. 
C)  hemoglobin oxygenation is favored in environments with a greater carbon dioxide concentration. 
D)  hemoglobin protonation favors oxygen release.

Question 17

Which of the following is true of myoglobin?

Accepted Answer

A)  its Hill coefficient is less than that of hemoglobin 
B)  it carries the same amount of oxygen as hemoglobin on a molar basis 
C)  its binding of oxygen represents positive cooperativity 
D)  its binding of oxygen is affected by 2,3-BPG 
A)  its Hill coefficient is less than that of hemoglobin 
B)  it carries the same amount of oxygen as hemoglobin on a molar basis 
C)  its binding of oxygen represents positive cooperativity 
D)  its binding of oxygen is affected by 2,3-BPG

Question 18

The Bohr effect is due in part to

Accepted Answer

A)  relatively low pKa (i.e. weaker base) for histidyl residues because of their proximity to ionized aspartyl residues in oxyhemoglobin. 
B)  a relatively high pKa (i.e. stronger base) for histidyl residues because of their proximity to arginyl residues in deoxyhemoglobin. 
C)  a relatively high pKa for histidyl residues because of their proximity to ionized aspartyl residues in deoxyhemoglobin. 
D)  a relatively low pKa for histidyl residues because of their proximity to arginyl residues in deoxyhemoglobin. 
A)  relatively low pKa (i.e. weaker base) for histidyl residues because of their proximity to ionized aspartyl residues in oxyhemoglobin. 
B)  a relatively high pKa (i.e. stronger base) for histidyl residues because of their proximity to arginyl residues in deoxyhemoglobin. 
C)  a relatively high pKa for histidyl residues because of their proximity to ionized aspartyl residues in deoxyhemoglobin. 
D)  a relatively low pKa for histidyl residues because of their proximity to arginyl residues in deoxyhemoglobin.

Question 19

In the normal red blood cell, 2,3-BPG binds to alpha-amino groups of hemoglobin. What would happen to the O2-saturation curve of Hb in the presence of normal amounts of 2,3-BPG if a drug were administered that prevents the binding of 2,3-BPG to Hb?

Accepted Answer

A)  the curve would be shifted to the left from that of normal red cells 
B)  the concentration of O2 necessary to saturate Hb would be lower than that normally required 
C)  the amount of O2 delivered to the tissue for a given partial pressure of O2 (e.g., 40 mm Hg) would be lower than normal 
D)  all of the above 
E)  none of the above 
A)  the curve would be shifted to the left from that of normal red cells 
B)  the concentration of O2 necessary to saturate Hb would be lower than that normally required 
C)  the amount of O2 delivered to the tissue for a given partial pressure of O2 (e.g., 40 mm Hg) would be lower than normal 
D)  all of the above 
E)  none of the above

Question 20

The following statements about hemoglobin F (fetal Hb) are all true EXCEPT

Accepted Answer

A)  The P50 for O2 is closer to 20 torr than 27 torr which is the P50 for adult Hb. 
B)  The beta chains are identical to those in adult hemoglobin. 
C)  Some terminal amino groups are acetylated. 
D)  The positive charges in the BPG binding cleft are fewer than in adult hemoglobin. 
E)  The diminished ability to unload O2 is offset by a higher than adult concentration 
A)  The P50 for O2 is closer to 20 torr than 27 torr which is the P50 for adult Hb. 
B)  The beta chains are identical to those in adult hemoglobin. 
C)  Some terminal amino groups are acetylated. 
D)  The positive charges in the BPG binding cleft are fewer than in adult hemoglobin. 
E)  The diminished ability to unload O2 is offset by a higher than adult concentration

Exam 9: Protein II: Structure-Function Relationships in Protein Families

What happens when the substrate for a serine protease is denatured?

All of the following are true of the isohydric mechanism EXCEPT:

Which of the following hemoglobins normally predominates at the time of birth?

Laminin and fibronectin have which characteristic in common?

The affinity of hemoglobin for oxygen (O2) is increased by an increase in the concentration of

The part of the antigen that is recognized by the antibody is called

The part of the antigen that is recognized by the antibody is called

All of the following statements about the conversion of hemoglobin from taut to relaxed forms are correct, EXCEPT

What are the family of specific serine protease inhibitors called?

When the oxygen-saturation curve of hemoglobin is analyzed by use of the Hill equation, a Hill constant of about 3 is found. This means that

Which of the following statements about hemoglobin is true?

All of the following are true regarding IgM's EXCEPT which one?

Carbon monoxide is toxic because

The predominant class of antibody produced in the primary immune response is

The complementarity-determining regions of an immunoglobulin G molecule The complementarity-determining regions of an immunoglobulin G molecule

Which of the following statements about the Bohr effect is TRUE?

Which of the following is true of myoglobin?

The Bohr effect is due in part to

In the normal red blood cell, 2,3-BPG binds to alpha-amino groups of hemoglobin. What would happen to the O2-saturation curve of Hb in the presence of normal amounts of 2,3-BPG if a drug were administered that prevents the binding of 2,3-BPG to Hb?

The following statements about hemoglobin F (fetal Hb) are all true EXCEPT

Eukaryotic Cell Structure

DNA and RNA: Composition and Structure

Protein I: Composition and Structure

DNA Replication, Recombination, and Repair

RNA: Transcription and Rna Processing

Protein Synthesis: Translation and Posttranslational Modifications

Recombinant Dna and Biotechnology

Regulation of Gene Expression

Enzymes: Classification, Kinetics, and Control

The Cytochromes P450 and Nitric Oxide Synthases

Biological Membranes: Structure and Membrane Transport

Fundamentals of Signal Transduction

Bioenergetics and Oxidative Metabolism

Carbohydrate Metabolism I: Major Metabolic Pathways and Their Control

Carbohydrate Metabolism II: Special Pathways and Glycoconjugates

Lipid Metabolism I: Synthesis, Storage, and Utilization of Fatty Acids and Triacylglycerols

Lipid Metabolism II: Pathways of Metabolism of Special Lipids

Amino Acid Metabolism

Purine and Pyrimidine Nucleotide Metabolism

Metabolic Interrelationships

Biochemistry of Hormones

Molecular Cell Biology

Cell Cycle, Programmed Cell Death, and Cancer

Digestion and Absorption of Basic Nutritional Constituents

Digestion and Absorption of Basic Nutritional Constituents

Principles of Nutrition I and II

Filters

The affinity of hemoglobin for oxygen (O₂) is increased by an increase in the concentration of