Question 1

X-ray crystallography is used to determine protein structure because

Accepted Answer

A)  it can be done on dilute solutions 
B)  it requires no calculations 
C)  the positions of all atoms can be found by this method 
D)  all of these 
A)  it can be done on dilute solutions 
B)  it requires no calculations 
C)  the positions of all atoms can be found by this method 
D)  all of these

Question 2

The following bond forces are important in tertiary structure:

Accepted Answer

A)  Disulfide bonds 
B)  Hydrogen bonds 
C)  Hydrophobic attraction 
D)  Both hydrogen bonds and hydrophobic attraction. 
E)  All of these are important in tertiary structure 
A)  Disulfide bonds 
B)  Hydrogen bonds 
C)  Hydrophobic attraction 
D)  Both hydrogen bonds and hydrophobic attraction. 
E)  All of these are important in tertiary structure

Question 3

Disulfide bonds are most important in this type of structure:

Accepted Answer

A)  primary structure 
B)  secondary structure 
C)  tertiary structure 
D)  quaternary structure 
E)  All of these 
A)  primary structure 
B)  secondary structure 
C)  tertiary structure 
D)  quaternary structure 
E)  All of these

Question 4

Which of the following amino acid residues would most likely be found in the interior of a globular protein?

Accepted Answer

A)  glutamic acid 
B)  lysine 
C)  leucine 
D)  serine 
A)  glutamic acid 
B)  lysine 
C)  leucine 
D)  serine

Question 5

Exhibit 4B   Refer to Exhibit 4B.The type of bonding labeled "N" in these figure is:

Accepted Answer

A)  Hydrogen bonding of the peptide backbone 
B)  Covalent bonding involving the R-groups 
C)  Hydrophobic interactions 
D)  Metal ion coordination 
E)  Electrostatic attraction 
A)  Hydrogen bonding of the peptide backbone 
B)  Covalent bonding involving the R-groups 
C)  Hydrophobic interactions 
D)  Metal ion coordination 
E)  Electrostatic attraction

Question 6

The following bond forces are important in quaternary structure:

Accepted Answer

A)  Disulfide bonds 
B)  Hydrogen bonds 
C)  Hydrophobic attraction 
D)  Both hydrogen bonds and hydrophobic attraction. 
E)  All of these are important in quaternary structure. 
A)  Disulfide bonds 
B)  Hydrogen bonds 
C)  Hydrophobic attraction 
D)  Both hydrogen bonds and hydrophobic attraction. 
E)  All of these are important in quaternary structure.

Question 7

The tertiary structure of a protein is usually a result of which of the following interactions?

Accepted Answer

A)  intramolecular hydrogen bonding 
B)  electrostatic interactions 
C)  hydrophobic interactions 
D)  all of these 
A)  intramolecular hydrogen bonding 
B)  electrostatic interactions 
C)  hydrophobic interactions 
D)  all of these

Question 8

Which of the following is true?

Accepted Answer

A)  The collagen helix and the a-helix are the only types of helices in proteins. 
B)  Globular proteins tend to be water soluble 
C)  Globular and fibrous are examples of secondary structure 
D)  All of these 
A)  The collagen helix and the a-helix are the only types of helices in proteins. 
B)  Globular proteins tend to be water soluble 
C)  Globular and fibrous are examples of secondary structure 
D)  All of these

Question 9

Hydrogen bonds are most important in this type of structure in proteins:

Accepted Answer

A)  primary structure 
B)  secondary structure 
C)  tertiary structure 
D)  quaternary structure 
E)  All of these 
A)  primary structure 
B)  secondary structure 
C)  tertiary structure 
D)  quaternary structure 
E)  All of these

Question 10

Which of the following amino acids is unlikely to be found in an a-helix due to its cyclic structure?

Accepted Answer

A)  phenylalanine 
B)  tryptophan 
C)  proline 
D)  lysine 
A)  phenylalanine 
B)  tryptophan 
C)  proline 
D)  lysine

Question 11

The following amino acid causes a kink or bend in the a-helix.

Accepted Answer

A)  Ala 
B)  Glu 
C)  Lys 
D)  Pro 
E)  Trp 
A)  Ala 
B)  Glu 
C)  Lys 
D)  Pro 
E)  Trp

Question 12

In allosteric interactions

Accepted Answer

A)  proteins that consist of a single polypeptide chain form aggregates. 
B)  disulfide bonds are broken. 
C)  changes that take place in one site of a protein cause changes at a distant site. 
D)  metal ions always bind to the protein. 
A)  proteins that consist of a single polypeptide chain form aggregates. 
B)  disulfide bonds are broken. 
C)  changes that take place in one site of a protein cause changes at a distant site. 
D)  metal ions always bind to the protein.

Question 13

Which of the following best describes what happens when hemoglobin binds bisphosphoglyceric acid (BPG)?

Accepted Answer

A)  Binding of BPG leads to tighter binding of oxygen. 
B)  Binding of BPG allows maternal (adult) Hb to bind oxygen more tightly than fetal Hb. 
C)  Binding of BPG causes oxygen to dissociate from Hb. 
D)  Binding of BPG causes the subunits of hemoglobin to separate. 
A)  Binding of BPG leads to tighter binding of oxygen. 
B)  Binding of BPG allows maternal (adult) Hb to bind oxygen more tightly than fetal Hb. 
C)  Binding of BPG causes oxygen to dissociate from Hb. 
D)  Binding of BPG causes the subunits of hemoglobin to separate.

Question 14

Hemoglobin differs from myoglobin because

Accepted Answer

A)  it does not have a heme group. 
B)  it is a tetramer, whereas myoglobin is a single polypeptide chain. 
C)  it does not contain any helical regions. 
D)  it contains more b-pleated sheet structure. 
A)  it does not have a heme group. 
B)  it is a tetramer, whereas myoglobin is a single polypeptide chain. 
C)  it does not contain any helical regions. 
D)  it contains more b-pleated sheet structure.

Question 15

Which of the following statements regarding hemoglobin (Hb) and myoglobin (Mb) is true?

Accepted Answer

A)  Mb transports oxygen while Hb stores it. 
B)  Mb has quaternary structure but Hb does not. 
C)  Mb displays simple kinetics of binding while Hb displays cooperativity. 
D)  Mb binds Fe(II) while Hb binds heme. 
A)  Mb transports oxygen while Hb stores it. 
B)  Mb has quaternary structure but Hb does not. 
C)  Mb displays simple kinetics of binding while Hb displays cooperativity. 
D)  Mb binds Fe(II) while Hb binds heme.

Question 16

Fibrous proteins

Accepted Answer

A)  are always composed of helical structures. 
B)  are always composed of b-sheets. 
C)  can be composed of either helical or b-sheet structures. 
A)  are always composed of helical structures. 
B)  are always composed of b-sheets. 
C)  can be composed of either helical or b-sheet structures.

Question 17

Two amino acids frequently found in reverse turns are

Accepted Answer

A)  tyrosine and tryptophan 
B)  serine and threonine 
C)  glycine and proline 
D)  leucine and isoleucine 
A)  tyrosine and tryptophan 
B)  serine and threonine 
C)  glycine and proline 
D)  leucine and isoleucine

Question 18

Generally speaking,this type of protein is water-soluble:

Accepted Answer

A)  Fibrous. 
B)  Globular. 
C)  Both fibrous and globular proteins are usually water-soluble. 
D)  Neither fibrous nor globular proteins are usually water-soluble. 
E)  You cannot generalize about the solubility of fibrous or globular proteins. 
A)  Fibrous. 
B)  Globular. 
C)  Both fibrous and globular proteins are usually water-soluble. 
D)  Neither fibrous nor globular proteins are usually water-soluble. 
E)  You cannot generalize about the solubility of fibrous or globular proteins.

Question 19

Which of the following can result in protein denaturation?

Accepted Answer

A)  heat 
B)  extremes of pH 
C)  detergents 
D)  all of the above 
A)  heat 
B)  extremes of pH 
C)  detergents 
D)  all of the above

Question 20

Which of the following proteins is not homologous with the others?

Accepted Answer

A)  myoglogin 
B)  a-chain of hemoglobin 
C)  b-chain of hemoglobin 
D)  collagen 
A)  myoglogin 
B)  a-chain of hemoglobin 
C)  b-chain of hemoglobin 
D)  collagen

Exam 4: The Three-Dimensional Structure of Proteins

X-ray crystallography is used to determine protein structure because

The following bond forces are important in tertiary structure:

Disulfide bonds are most important in this type of structure:

Which of the following amino acid residues would most likely be found in the interior of a globular protein?

Exhibit 4B Refer to Exhibit 4B.The type of bonding labeled "N" in these figure is:

The following bond forces are important in quaternary structure:

The tertiary structure of a protein is usually a result of which of the following interactions?

Which of the following is true?

Hydrogen bonds are most important in this type of structure in proteins:

Which of the following amino acids is unlikely to be found in an a-helix due to its cyclic structure?

The following amino acid causes a kink or bend in the a-helix.

In allosteric interactions

Which of the following best describes what happens when hemoglobin binds bisphosphoglyceric acid (BPG)?

Hemoglobin differs from myoglobin because

Which of the following statements regarding hemoglobin (Hb) and myoglobin (Mb) is true?

Fibrous proteins

Two amino acids frequently found in reverse turns are

Generally speaking,this type of protein is water-soluble:

Which of the following can result in protein denaturation?

Which of the following proteins is not homologous with the others?

Biochemistry and the Organization of Cells

Water: The Solvent for Biochemical Reactions

Amino Acids and Peptides

Protein Purification and Characterization Techniques

The Behavior of Proteins: Enzymes

The Behavior of Proteins: Enzymes, Mechanisms, and Control

Lipids and Proteins Are Associated in Biological Membranes

Nucleic Acids: How Structure Conveys Information

Biosynthesis of Nucleic Acids: Replication

Transcription of the Genetic Code: Biosynthesis of Rna

Protein Synthesis: Translation of the Genetic Message

Nucleic Acid Biotechnology Techniques

Viruses, Cancer, and Immunology

The Importance of Energy Changes and Electron Transfer in Metabolism

Carbohydrates

Glycolysis

Storage Mechanisms and Control in Carbohydrate Metabolism

The Citric Acid Cycle

Electron Transport and Oxidative Phosphorylation

Lipid Metabolism

Photosynthesis

The Metabolism of Nitrogen

Integration of Metabolism: Cellular Signaling

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