Question 1

Which statement is NOT correct concerning 2,3-bisphosphoglycerate (BPG)?

Accepted Answer

A)  It binds at a distance from the heme groups of hemoglobin. 
B)  It binds with lower affinity to fetal hemoglobin than to adult hemoglobin. 
C)  It increases the affinity of hemoglobin for oxygen. 
D)  It is an allosteric modulator. 
E)  It is normally found associated with the hemoglobin extracted from red blood cells. 
A)  It binds at a distance from the heme groups of hemoglobin. 
B)  It binds with lower affinity to fetal hemoglobin than to adult hemoglobin. 
C)  It increases the affinity of hemoglobin for oxygen. 
D)  It is an allosteric modulator. 
E)  It is normally found associated with the hemoglobin extracted from red blood cells.

Question 2

(a) What is the effect of pH on the binding of oxygen to hemoglobin (the Bohr Effect)? (b) Briefly describe the mechanism of this effect.

Accepted Answer

(a) The effect of pH on the binding of o

Question 3

For the binding of a ligand to a protein, what is the relationship between the Ka (association constant), the Kd (dissociation constant), and the affinity of the protein for the ligand?

Accepted Answer

The relationship between the association

Question 4

What is the role of ATP and ATP hydrolysis in the cycle of actin-myosin association and disassociation that leads to muscle contraction?

Accepted Answer

ATP (adenosine triphosphate) plays a cru

Question 5

During muscle contraction, the _____ of myofibrils contract and the _____ move closer together due to the movement of myosin thick filaments along actin thin filaments.

Accepted Answer

A)  Z disks; A bands 
B)  A bands; M lines 
C)  I bands; Z disks 
D)  I bands; M lines 
E)  M lines; I bands 
A)  Z disks; A bands 
B)  A bands; M lines 
C)  I bands; Z disks 
D)  I bands; M lines 
E)  M lines; I bands

Question 6

A test where antibodies are used to quantitatively detect the presence of antiviral antibodies in human blood samples is referred to as:

Accepted Answer

A)  Western blot. 
B)  ELISA. 
C)  Northern blot. 
D)  FRET. 
E)  PCR. 
A)  Western blot. 
B)  ELISA. 
C)  Northern blot. 
D)  FRET. 
E)  PCR.

Question 7

Explain why most multicellular organisms use an iron-containing protein for oxygen binding rather than free Fe2+. Your answer should include an explanation of (a) the role of heme and (b) the role of the protein itself.

Accepted Answer

Most multicellular organisms use an iron

Question 8

Which molecule binds MOST strongly to the heme iron?

Accepted Answer

A)  N2 
B)  O2 
C)  CO2 
D)  CO 
E)  H2O 
A)  N2 
B)  O2 
C)  CO2 
D)  CO 
E)  H2O

Question 9

Explain briefly why the relative affinity of heme for oxygen and carbon monoxide is changed by the presence of the myoglobin protein.

Accepted Answer

The relative affinity of heme for oxygen

Question 10

Which immune-system cells are responsible for producing antibodies?

Accepted Answer

A)  macrophages 
B)  B cells 
C)  helper T cells 
D)  cytotoxic T cells 
E)  erythrocytes 
A)  macrophages 
B)  B cells 
C)  helper T cells 
D)  cytotoxic T cells 
E)  erythrocytes

Question 11

Which class of proteins includes the LARGEST polypeptide chains discovered to date in humans?

Accepted Answer

A)  myosins 
B)  actins 
C)  titins 
D)  troponins 
E)  globins 
A)  myosins 
B)  actins 
C)  titins 
D)  troponins 
E)  globins

Question 12

Which part of the IgG molecule is NOT involved in binding to an antigen?

Accepted Answer

A)  Fab 
B)  Fc 
C)  heavy chain 
D)  light chain 
E)  variable domain 
A)  Fab 
B)  Fc 
C)  heavy chain 
D)  light chain 
E)  variable domain

Question 13

Which antibody is principally found in saliva, tears, and breast milk?

Accepted Answer

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

Question 14

Antibodies against a specific antigen can be injected into a person to provide passive immunity. For which reason is this NOT as effective as the process of vaccination with that antigen?

Accepted Answer

A)  Injection of antibodies does not provide long-lasting immunity. 
B)  Vaccination with antigens triggers a clonal selection of B cells and cytotoxic T cells. 
C)  Injection of antibodies may cause allergic reactions, while vaccination never causes allergic reactions. 
D)  Injection of antibodies does not provide long-lasting immunity, and vaccination with antigens triggers a clonal selection of B cells and cytotoxic T cells. 
E)  Injection of antibodies does not provide long-lasting immunity and may cause allergic reactions, while vaccination never causes allergic reactions. 
A)  Injection of antibodies does not provide long-lasting immunity. 
B)  Vaccination with antigens triggers a clonal selection of B cells and cytotoxic T cells. 
C)  Injection of antibodies may cause allergic reactions, while vaccination never causes allergic reactions. 
D)  Injection of antibodies does not provide long-lasting immunity, and vaccination with antigens triggers a clonal selection of B cells and cytotoxic T cells. 
E)  Injection of antibodies does not provide long-lasting immunity and may cause allergic reactions, while vaccination never causes allergic reactions.

Question 15

Describe the cycle of actin-myosin association and disassociation that leads to muscle contraction.

Accepted Answer

The cycle of actin-myosin association an

Question 16

The Fab regions of an antibody are made of which protein chain?

Accepted Answer

A)  a light chain containing variable and constant regions 
B)  a heavy chain containing variable and constant regions 
C)  a heavy chain containing only constant regions 
D)  both a light chain and a heavy chain containing variable and constant regions 
E)  both a light chain containing variable and constant regions and a heavy chain containing only constant regions 
A)  a light chain containing variable and constant regions 
B)  a heavy chain containing variable and constant regions 
C)  a heavy chain containing only constant regions 
D)  both a light chain and a heavy chain containing variable and constant regions 
E)  both a light chain containing variable and constant regions and a heavy chain containing only constant regions

Question 17

Which statement about protein-ligand binding is CORRECT?

Accepted Answer

A)  The Ka is equal to the concentration of ligand when all of the binding sites are occupied. 
B)  The Ka is independent of such conditions as salt concentration and pH. 
C)  The larger the Ka (association constant), the weaker the affinity. 
D)  The larger the Ka, the faster is the binding. 
E)  The larger the Ka, the smaller the Kd (dissociation constant). 
A)  The Ka is equal to the concentration of ligand when all of the binding sites are occupied. 
B)  The Ka is independent of such conditions as salt concentration and pH. 
C)  The larger the Ka (association constant), the weaker the affinity. 
D)  The larger the Ka, the faster is the binding. 
E)  The larger the Ka, the smaller the Kd (dissociation constant).

Question 18

Describe briefly the two principal models for the cooperative binding of ligands to proteins with multiple binding sites.

Accepted Answer

The two principal models for the coopera

Question 19

The fundamental cause of sickle-cell disease is a change in the structure of:

Accepted Answer

A)  blood. 
B)  capillaries. 
C)  hemoglobin. 
D)  red cells. 
E)  the heart. 
A)  blood. 
B)  capillaries. 
C)  hemoglobin. 
D)  red cells. 
E)  the heart.

Question 20

Which statement is NOT correct concerning cooperative binding of a ligand to a protein?

Accepted Answer

A)  It is usually a form of allosteric interaction. 
B)  It is usually associated with proteins with multiple subunits. 
C)  It rarely occurs in enzymes. 
D)  It results in a nonlinear Hill Plot. 
E)  It results in a sigmoidal binding curve. 
A)  It is usually a form of allosteric interaction. 
B)  It is usually associated with proteins with multiple subunits. 
C)  It rarely occurs in enzymes. 
D)  It results in a nonlinear Hill Plot. 
E)  It results in a sigmoidal binding curve.

Exam 5: Protein Function

Which statement is NOT correct concerning 2,3-bisphosphoglycerate (BPG)?

(a) What is the effect of pH on the binding of oxygen to hemoglobin (the Bohr Effect)? (b) Briefly describe the mechanism of this effect.

For the binding of a ligand to a protein, what is the relationship between the Ka (association constant), the Kd (dissociation constant), and the affinity of the protein for the ligand?

What is the role of ATP and ATP hydrolysis in the cycle of actin-myosin association and disassociation that leads to muscle contraction?

During muscle contraction, the _____ of myofibrils contract and the _____ move closer together due to the movement of myosin thick filaments along actin thin filaments.

A test where antibodies are used to quantitatively detect the presence of antiviral antibodies in human blood samples is referred to as:

Explain why most multicellular organisms use an iron-containing protein for oxygen binding rather than free Fe2+. Your answer should include an explanation of (a) the role of heme and (b) the role of the protein itself.

Which molecule binds MOST strongly to the heme iron?

Explain briefly why the relative affinity of heme for oxygen and carbon monoxide is changed by the presence of the myoglobin protein.

Which immune-system cells are responsible for producing antibodies?

Which class of proteins includes the LARGEST polypeptide chains discovered to date in humans?

Which part of the IgG molecule is NOT involved in binding to an antigen?

Which antibody is principally found in saliva, tears, and breast milk?

Antibodies against a specific antigen can be injected into a person to provide passive immunity. For which reason is this NOT as effective as the process of vaccination with that antigen?

Describe the cycle of actin-myosin association and disassociation that leads to muscle contraction.

The Fab regions of an antibody are made of which protein chain?

Which statement about protein-ligand binding is CORRECT?

Describe briefly the two principal models for the cooperative binding of ligands to proteins with multiple binding sites.

The fundamental cause of sickle-cell disease is a change in the structure of:

Which statement is NOT correct concerning cooperative binding of a ligand to a protein?

The Foundations of Biochemistry

Water

Amino Acids, Peptides, and Proteins

The Three-Dimensional Structure of Proteins

Enzymes

Carbohydrates and Glycobiology

Nucleotides and Nucleic Acids

DNA-Based Information Technologies

Lipids

Biological Membranes and Transport

Biosignaling

Bioenergetics and Biochemical Reaction Types

Glycolysis, Gluconeogenesis, and the Pentose Phosphate Pathway

Principles of Metabolic Regulation

The Citric Acid Cycle

Fatty Acid Catabolism

Amino Acid Oxidation and the Production of Urea

Oxidative Phosphorylation and Photophosphorylation

Carbohydrate Biosynthesis in Plants and Bacteria

Lipid Biosynthesis

Biosynthesis of Amino Acids, Nucleotides, and Related Molecules

Hormonal Regulation and Integration of Mammalian Metabolism

Genes and Chromosomes

DNA Metabolism

RNA Metabolism

Protein Metabolism

Regulation of Gene Expression

Filters

For the binding of a ligand to a protein, what is the relationship between the K_a (association constant), the K_d (dissociation constant), and the affinity of the protein for the ligand?

During muscle contraction, the _ of myofibrils contract and the _ move closer together due to the movement of myosin thick filaments along actin thin filaments.

Explain why most multicellular organisms use an iron-containing protein for oxygen binding rather than free Fe²⁺. Your answer should include an explanation of (a) the role of heme and (b) the role of the protein itself.