Question 1

Homologous proteins can be identified not only by sequencing,but also by comparing similarities in tertiary structure.

Accepted Answer

A) True 
 B)False

Question 2

A fold in a protein is a combination of secondary structures that form the core of a protein domain.

Accepted Answer

A) True 
 B)False

Question 3

How many complete turns are there in an ideal α-helix that contains 15 amino acids and has a pitch of 0.54 nm and a rise of 0.15 nm?

Accepted Answer

A) 1 
B) 4 
C) 8 
D) 59 
A) 1 
B) 4 
C) 8 
D) 59

Question 4

Structural proteins that typically assemble into large cables or threads to provide mechanical support to cells or organisms are classified as ________ proteins.

Accepted Answer

A) fibrous 
B) enzyme 
C) globular 
D) β-strand 
A) fibrous 
B) enzyme 
C) globular 
D) β-strand

Question 5

Match the protein organization most associated with the term(s)listed below:
-Subunits

Accepted Answer

A) Secondary 
B) Tertiary 
C) Quaternary 
D) Primary 
A) Secondary 
B) Tertiary 
C) Quaternary 
D) Primary

Question 6

The distance along a helix axis for one complete turn is called the ________.

Accepted Answer

A) axial distance 
B) rise 
C) screw length 
D) pitch 
A) axial distance 
B) rise 
C) screw length 
D) pitch

Question 7

Match each level of organization with a description.
-Primary structure

Accepted Answer

A) Specific order of amino acids 
B) Multiple subunits are present 
C) Overall shape of a protein 
D) Repeated pattern of folding 
A) Specific order of amino acids 
B) Multiple subunits are present 
C) Overall shape of a protein 
D) Repeated pattern of folding

Question 8

Which statement is false about the heme group?

Accepted Answer

A) When oxygen binds to heme,the iron ion is oxidized from Fe²+ to Fe ³+. 
B) If exposed to air,a free heme group (not associated with hemoglobin)is readily oxidized converting Fe²+ to Fe ³+ and can no longer bind oxygen. 
C) The heme group is tightly,but non-covalently,held in myoglobin molecule. 
D) The chemical structure of the heme groups in myoglobin and hemoglobin are identical. 
A) When oxygen binds to heme,the iron ion is oxidized from Fe²+ to Fe ³+. 
B) If exposed to air,a free heme group (not associated with hemoglobin)is readily oxidized converting Fe²+ to Fe ³+ and can no longer bind oxygen. 
C) The heme group is tightly,but non-covalently,held in myoglobin molecule. 
D) The chemical structure of the heme groups in myoglobin and hemoglobin are identical.

Question 9

What feature does a Ramachandran plot display?

Accepted Answer

A) Allowed angles of phi and psi for a polypeptide backbone. 
B) Preferred amino acids in an α-helix. 
C) The hydropathy of amino acids. 
D) The variation of pH versus volume of base added during titration to determine the pKa. 
A) Allowed angles of phi and psi for a polypeptide backbone. 
B) Preferred amino acids in an α-helix. 
C) The hydropathy of amino acids. 
D) The variation of pH versus volume of base added during titration to determine the pKa.

Question 10

Which demonstrates that the primary structure of a protein determines its tertiary structure?

Accepted Answer

A) How the disulfide bonds hold it in the correct shape. 
B) Proteins can refold even when the amino acid sequence is changed. 
C) Proteins refold when the amino acid sequence is the same as in the native conformation. 
D) Chaotropic agents cannot denature the native conformation. 
E) All of the above. 
A) How the disulfide bonds hold it in the correct shape. 
B) Proteins can refold even when the amino acid sequence is changed. 
C) Proteins refold when the amino acid sequence is the same as in the native conformation. 
D) Chaotropic agents cannot denature the native conformation. 
E) All of the above.

Question 11

Protein X can bind to either protein A or protein B to form a complex.The association constants are 108 M-1 (X with A)and 106 M-1 (X with B).Which statement is true?

Accepted Answer

A) In the presence of excess X,it takes fewer molecules of A than B to generate a given amount of complex. 
B) The dissociation constant of the complex XA is higher than that of complex XB. 
C) B must be a larger protein than A. 
D) The values of the association constants indicate that both complexes XA and XB are very unstable in small cells like E.coli. 
A) In the presence of excess X,it takes fewer molecules of A than B to generate a given amount of complex. 
B) The dissociation constant of the complex XA is higher than that of complex XB. 
C) B must be a larger protein than A. 
D) The values of the association constants indicate that both complexes XA and XB are very unstable in small cells like E.coli.

Question 12

At high carbon dioxide concentrations the carbamates of hemoglobin can be formed.The carbamates of oxyhemoglobin are less stable than those of deoxyhemoglobin.

Accepted Answer

A) True 
 B)False

Question 13

A hyperbolic binding curve differs from a sigmoidal binding curve in that the hyperbolic curve

Accepted Answer

A) has a single equilibrium constant for oxygen binding. 
B) binds more oxygen after the initial proteins first bind oxygen. 
C) shows cooperativity. 
D) binds up to four molecules of oxygen. 
E) All of the above. 
A) has a single equilibrium constant for oxygen binding. 
B) binds more oxygen after the initial proteins first bind oxygen. 
C) shows cooperativity. 
D) binds up to four molecules of oxygen. 
E) All of the above.

Question 14

Water can easily penetrate and even pass through the interior of a folded protein.

Accepted Answer

A) True 
 B)False

Question 15

Chaperones are proteins which

Accepted Answer

A) renature any denatured proteins. 
B) help cells repair damage due to heat shock. 
C) assist protein self assembly. 
D) use ATP to fold proteins. 
E) All of the above. 
A) renature any denatured proteins. 
B) help cells repair damage due to heat shock. 
C) assist protein self assembly. 
D) use ATP to fold proteins. 
E) All of the above.

Question 16

Which statement is not true about the peptide bond?

Accepted Answer

A) The peptide bond has partial double-bond character. 
B) The peptide bond is longer than the typical carbon-nitrogen bond. 
C) Rotation is restricted about the peptide bond. 
D) The carbonyl oxygen and the amide hydrogen are most often in a trans configuration with respect to one another. 
A) The peptide bond has partial double-bond character. 
B) The peptide bond is longer than the typical carbon-nitrogen bond. 
C) Rotation is restricted about the peptide bond. 
D) The carbonyl oxygen and the amide hydrogen are most often in a trans configuration with respect to one another.

Homologous proteins can be identified not only by sequencing,but also by comparing similarities in tertiary structure.

A fold in a protein is a combination of secondary structures that form the core of a protein domain.

How many complete turns are there in an ideal α-helix that contains 15 amino acids and has a pitch of 0.54 nm and a rise of 0.15 nm?

Structural proteins that typically assemble into large cables or threads to provide mechanical support to cells or organisms are classified as ________ proteins.

Match the protein organization most associated with the term(s)listed below: -Subunits

The distance along a helix axis for one complete turn is called the ________.

Match each level of organization with a description. -Primary structure

Which statement is false about the heme group?

What feature does a Ramachandran plot display?

Which demonstrates that the primary structure of a protein determines its tertiary structure?

Protein X can bind to either protein A or protein B to form a complex.The association constants are 108 M-1 (X with A)and 106 M-1 (X with B).Which statement is true?

At high carbon dioxide concentrations the carbamates of hemoglobin can be formed.The carbamates of oxyhemoglobin are less stable than those of deoxyhemoglobin.

A hyperbolic binding curve differs from a sigmoidal binding curve in that the hyperbolic curve

Water can easily penetrate and even pass through the interior of a folded protein.

Chaperones are proteins which

Which statement is not true about the peptide bond?

Introduction to Biochemistry

Water

Amino Acids and the Primary Structures of Proteins

Properties of Enzymes

Mechanisms of Enzymes

Coenzymes and Vitamins

Carbohydrates

Lipids and Membranes

Introduction to Metabolism

Glycolysis

Gluconeogenesis, the Pentose Phosphate Pathway, and Glycogen Metabolism

The Citric Acid Cycle

Electron Transport and Atp Synthesis

Photosynthesis

Lipid Metabolism

Amino Acid Metabolism

Nucleotide Metabolism

Nucleic Acids

DNA Replication, repair, and Recombination

Transcription and RNA Processing

Protein Synthesis

Filters

Exam 4: Proteins: Three-Dimensional Structure and Function

Homologous proteins can be identified not only by sequencing,but also by comparing similarities in tertiary structure.

A fold in a protein is a combination of secondary structures that form the core of a protein domain.

How many complete turns are there in an ideal α-helix that contains 15 amino acids and has a pitch of 0.54 nm and a rise of 0.15 nm?

Structural proteins that typically assemble into large cables or threads to provide mechanical support to cells or organisms are classified as ________ proteins.

Match the protein organization most associated with the term(s)listed below: -Subunits

The distance along a helix axis for one complete turn is called the ________.

Match each level of organization with a description. -Primary structure

Which statement is false about the heme group?

What feature does a Ramachandran plot display?

Which demonstrates that the primary structure of a protein determines its tertiary structure?

Protein X can bind to either protein A or protein B to form a complex.The association constants are 108 M-1 (X with A)and 106 M-1 (X with B).Which statement is true?

At high carbon dioxide concentrations the carbamates of hemoglobin can be formed.The carbamates of oxyhemoglobin are less stable than those of deoxyhemoglobin.

A hyperbolic binding curve differs from a sigmoidal binding curve in that the hyperbolic curve

Water can easily penetrate and even pass through the interior of a folded protein.

Chaperones are proteins which

Which statement is not true about the peptide bond?

Introduction to Biochemistry

Water

Amino Acids and the Primary Structures of Proteins

Properties of Enzymes

Mechanisms of Enzymes

Coenzymes and Vitamins

Carbohydrates

Lipids and Membranes

Introduction to Metabolism

Glycolysis

Gluconeogenesis, the Pentose Phosphate Pathway, and Glycogen Metabolism

The Citric Acid Cycle

Electron Transport and Atp Synthesis

Photosynthesis

Lipid Metabolism

Amino Acid Metabolism

Nucleotide Metabolism

Nucleic Acids

DNA Replication, repair, and Recombination

Transcription and RNA Processing

Protein Synthesis

Filters