Question 1

An allosteric interaction between a ligand and a protein is one in which:

Accepted Answer

A)  binding of a molecule to a binding site affects binding of additional molecules to the same site. 
B)  binding of a molecule to a binding site affects binding properties of another site on the protein. 
C)  binding of the ligand to the protein is covalent. 
D)  multiple molecules of the same ligand can bind to the same binding site. 
E)  two different ligands can bind to the same binding site. 
A)  binding of a molecule to a binding site affects binding of additional molecules to the same site. 
B)  binding of a molecule to a binding site affects binding properties of another site on the protein. 
C)  binding of the ligand to the protein is covalent. 
D)  multiple molecules of the same ligand can bind to the same binding site. 
E)  two different ligands can bind to the same binding site.

Question 2

Myoglobin and the subunits of hemoglobin have:

Accepted Answer

A)  no obvious structural relationship. 
B)  very different primary and tertiary structures. 
C)  very similar primary and tertiary structures. 
D)  very similar primary structures, but different tertiary structures. 
E)  very similar tertiary structures, but different primary structures. 
A)  no obvious structural relationship. 
B)  very different primary and tertiary structures. 
C)  very similar primary and tertiary structures. 
D)  very similar primary structures, but different tertiary structures. 
E)  very similar tertiary structures, but different primary structures.

Question 3

Which generalization concerning motor proteins is CORRECT?

Accepted Answer

A)  They convert chemical energy into kinetic energy. 
B)  They convert chemical energy into potential energy. 
C)  They convert kinetic energy into chemical energy. 
D)  They convert kinetic energy into rotational energy. 
E)  They convert potential energy into chemical energy. 
A)  They convert chemical energy into kinetic energy. 
B)  They convert chemical energy into potential energy. 
C)  They convert kinetic energy into chemical energy. 
D)  They convert kinetic energy into rotational energy. 
E)  They convert potential energy into chemical energy.

Question 4

The coordinated nitrogen atoms in the heme prosthetic group have _____ character, which prevents conversion of the heme iron from the _____ state to the _____ state

Accepted Answer

A)  electron-donating; Fe2+; Fe3+ 
B)  electron-donating; Fe3+; Fe2+ 
C)  electron-accepting; Fe2+; Fe3+ 
D)  electron-accepting; Fe3+; Fe2+ 
E)  electron-accepting; Fe+; Fe0 
A)  electron-donating; Fe2+; Fe3+ 
B)  electron-donating; Fe3+; Fe2+ 
C)  electron-accepting; Fe2+; Fe3+ 
D)  electron-accepting; Fe3+; Fe2+ 
E)  electron-accepting; Fe+; Fe0

Question 5

Which protein undergoes a conformational change upon interacting with Ca2+, leading to stimulation of muscle contraction?

Accepted Answer

A)  actin 
B)  myosin 
C)  troponin 
D)  hemoglobin 
E)  immunoglobin 
A)  actin 
B)  myosin 
C)  troponin 
D)  hemoglobin 
E)  immunoglobin

Question 6

Which event triggers a "power stroke" in myosin?

Accepted Answer

A)  hydrolysis of ATP 
B)  binding of ATP 
C)  release of ADP 
D)  release of Pi 
E)  degradation of actin 
A)  hydrolysis of ATP 
B)  binding of ATP 
C)  release of ADP 
D)  release of Pi 
E)  degradation of actin

Question 7

Myosin obtains its high tensile strength due to its composition of:

Accepted Answer

A)  $\alpha$ helices supercoiled around each other in a left-handed coiled coil. 
B)  $\beta$strands layered on top of each other. 
C) $\alpha$ helices supercoiled around each other in a right-handed coiled coil. 
D)  $\beta$strands coiled around each other in a $\beta$-barrel conformation. 
E)  $\beta$ helices supercoiled around each other in a right-handed coiled coil. 
A)  $\alpha$ helices supercoiled around each other in a left-handed coiled coil. 
B)  $\beta$strands layered on top of each other. 
C) $\alpha$ helices supercoiled around each other in a right-handed coiled coil. 
D)  $\beta$strands coiled around each other in a $\beta$-barrel conformation. 
E)  $\beta$ helices supercoiled around each other in a right-handed coiled coil.

Question 8

Why is carbon monoxide (CO) toxic to aerobic organisms?

Accepted Answer

Carbon monoxide (CO) is toxic to aerobic

Question 9

IgG antibodies have _____ binding site(s) that is/are made up of the _____ regions of the light and heavy chains.

Accepted Answer

A)  one; variable 
B)  one; constant 
C)  two; variable 
D)  two; constant 
E)  one; diversity 
A)  one; variable 
B)  one; constant 
C)  two; variable 
D)  two; constant 
E)  one; diversity

Question 10

Which statement about antibodies is INCORRECT?

Accepted Answer

A)  Antibodies bind to antigens via induced fit. 
B)  Antibodies typically bind to antigens more strongly than enzymes bind to substrates. 
C)  Antibodies can be both soluble and membrane-bound. 
D)  Antibodies never release antigens once they are bound together. 
E)  More than 100 million different antibodies can be produced in humans. 
A)  Antibodies bind to antigens via induced fit. 
B)  Antibodies typically bind to antigens more strongly than enzymes bind to substrates. 
C)  Antibodies can be both soluble and membrane-bound. 
D)  Antibodies never release antigens once they are bound together. 
E)  More than 100 million different antibodies can be produced in humans.

Question 11

If a developing fetus made beta hemoglobin subunits instead of gamma hemoglobin subunits, what would be MOST likely to occur?

Accepted Answer

A)  The fetus would extract O2 from its mother's blood more effectively. 
B)  The fetal hemoglobin would have a higher affinity for 2,3-bisphosphoglycerate. 
C)  The fetal hemoglobin would have a lower affinity for CO. 
D)  The fetus would not be able to extract O2 from its mother's blood as effectively. 
E)  The fetus would be less susceptible to sickle cell anemia. 
A)  The fetus would extract O2 from its mother's blood more effectively. 
B)  The fetal hemoglobin would have a higher affinity for 2,3-bisphosphoglycerate. 
C)  The fetal hemoglobin would have a lower affinity for CO. 
D)  The fetus would not be able to extract O2 from its mother's blood as effectively. 
E)  The fetus would be less susceptible to sickle cell anemia.

Question 12

Describe how cooperativity of oxygen binding in hemoglobin is advantageous for the transport of oxygen from the lungs to the tissues and why myoglobin would not be a good protein to use for oxygen transport.

Accepted Answer

The cooperativity of oxygen binding in h

Question 13

Carbon monoxide (CO) is toxic to humans because it:

Accepted Answer

A)  binds to myoglobin and causes it to denature. 
B)  is rapidly converted to toxic CO2. 
C)  binds to the globin portion of hemoglobin and prevents the binding of O2. 
D)  binds to the Fe in hemoglobin and prevents the binding of O2. 
E)  binds to the heme portion of hemoglobin and causes heme to unbind from hemoglobin. 
A)  binds to myoglobin and causes it to denature. 
B)  is rapidly converted to toxic CO2. 
C)  binds to the globin portion of hemoglobin and prevents the binding of O2. 
D)  binds to the Fe in hemoglobin and prevents the binding of O2. 
E)  binds to the heme portion of hemoglobin and causes heme to unbind from hemoglobin.

Question 14

Imagine that you are an athlete competing in an international event that will take place at sea level. Without taking any performance-enhancing drugs or blood doping, what could you do in your training to enhance oxygen transport in your body? Describe what will chemically change in your blood as a result of your training and how this will enhance oxygen transport.

Accepted Answer

As an athlete competing at sea level, th

Question 15

Although the myosin molecule "walks" along actin in discrete steps, you are able to make smooth motions using your muscles. Explain how this is possible.

Accepted Answer

This is possible because the myosin mole

Question 16

The change in hemoglobin-binding affinity for oxygen due to changing pH and CO2 concentration in the blood is known as the:

Accepted Answer

A)  Hill hypothesis. 
B)  Messelson theory. 
C)  Bohr effect. 
D)  Higgs observation. 
E)  Boyle hypothesis. 
A)  Hill hypothesis. 
B)  Messelson theory. 
C)  Bohr effect. 
D)  Higgs observation. 
E)  Boyle hypothesis.

Question 17

The covalent bonds that hold antibody structures together are formed from which amino acid side chains?

Accepted Answer

A)  His 
B)  Thr 
C)  Cys 
D)  Met 
E)  Ser 
A)  His 
B)  Thr 
C)  Cys 
D)  Met 
E)  Ser

Question 18

The predominant structural feature in myosin molecules is:

Accepted Answer

A)  a $\beta$ structure. 
B)  an $\alpha$ helix. 
C)  the Fab domain. 
D)  the light chain. 
E)  the meromyosin domain. 
A)  a $\beta$ structure. 
B)  an $\alpha$ helix. 
C)  the Fab domain. 
D)  the light chain. 
E)  the meromyosin domain.

Question 19

Describe how immunoaffinity chromatography is performed.

Accepted Answer

Immunoaffinity chromatography is a techn

Question 20

Macrophages bind to the _____ region of IgG antibodies, thereby triggering phagocytosis of antibody-antigen complexes.

Accepted Answer

A)  Fab 
B)  Fc 
C)  epitope 
D)  hinge 
E)  antigen 
A)  Fab 
B)  Fc 
C)  epitope 
D)  hinge 
E)  antigen

Exam 5: Protein Function

An allosteric interaction between a ligand and a protein is one in which:

Myoglobin and the subunits of hemoglobin have:

Which generalization concerning motor proteins is CORRECT?

The coordinated nitrogen atoms in the heme prosthetic group have _____ character, which prevents conversion of the heme iron from the _____ state to the _____ state

Which protein undergoes a conformational change upon interacting with Ca2+, leading to stimulation of muscle contraction?

Which event triggers a "power stroke" in myosin?

Myosin obtains its high tensile strength due to its composition of:

Why is carbon monoxide (CO) toxic to aerobic organisms?

IgG antibodies have _____ binding site(s) that is/are made up of the _____ regions of the light and heavy chains.

Which statement about antibodies is INCORRECT?

If a developing fetus made beta hemoglobin subunits instead of gamma hemoglobin subunits, what would be MOST likely to occur?

Describe how cooperativity of oxygen binding in hemoglobin is advantageous for the transport of oxygen from the lungs to the tissues and why myoglobin would not be a good protein to use for oxygen transport.

Carbon monoxide (CO) is toxic to humans because it:

Although the myosin molecule "walks" along actin in discrete steps, you are able to make smooth motions using your muscles. Explain how this is possible.

The change in hemoglobin-binding affinity for oxygen due to changing pH and CO2 concentration in the blood is known as the:

The covalent bonds that hold antibody structures together are formed from which amino acid side chains?

The predominant structural feature in myosin molecules is:

Describe how immunoaffinity chromatography is performed.

Macrophages bind to the _____ region of IgG antibodies, thereby triggering phagocytosis of antibody-antigen complexes.

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

The coordinated nitrogen atoms in the heme prosthetic group have ___ character, which prevents conversion of the heme iron from the _ state to the ___ state

Which protein undergoes a conformational change upon interacting with Ca²⁺, leading to stimulation of muscle contraction?

IgG antibodies have _ binding site(s) that is/are made up of the _ regions of the light and heavy chains.

The change in hemoglobin-binding affinity for oxygen due to changing pH and CO₂ concentration in the blood is known as the: