Question 1

Which represents the backbone of a protein? Note: R = amino acid side chain N = nitrogen
Cα = alpha carbon C = carbonyl carbon

Accepted Answer

A)  R1R2R3R4R5  
B)  repeating units of N-C 
C)  repeating units of N-Cα-C 
D)  repeating units of Cα-C 
A)  R1R2R3R4R5  
B)  repeating units of N-C 
C)  repeating units of N-Cα-C 
D)  repeating units of Cα-C

Question 2

Match the protein organization most associated with the terms) listed below: A) Tertiary
B) Secondary
C) Primary
D) Quaternary
-Hydrogen bonds between carbonyl and amino groups

Accepted Answer

The answer of Match the protein organization most associated with...

Question 3

Chaperones are proteins which

Accepted Answer

A)  renature and 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 and 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 4

The main property of myoglobin and hemoglobin that makes them an efficient system for oxygen delivery from lungs to muscles is

Accepted Answer

A)  hydrophobicity. 
B)  different binding affinities for oxygen. 
C)  movement of the protein shapes. 
D)  cooperativity. 
E)  All of the above 
A)  hydrophobicity. 
B)  different binding affinities for oxygen. 
C)  movement of the protein shapes. 
D)  cooperativity. 
E)  All of the above

Question 5

The principle forces holding subunits of an oligomeric protein to each other are .

Accepted Answer

A)  peptide bonds 
B)  hydrophobic interactions 
C)  covalent bonds 
D)  disulfide bonds 
A)  peptide bonds 
B)  hydrophobic interactions 
C)  covalent bonds 
D)  disulfide bonds

Question 6

Which is true about the side chains of residues in an α-helix?

Accepted Answer

A)  They extend above or below the pleats. 
B)  They extend radially outward from the helix axis. 
C)  They point toward the center of the helix. 
D)  They hydrogen bond extensively with each other. 
A)  They extend above or below the pleats. 
B)  They extend radially outward from the helix axis. 
C)  They point toward the center of the helix. 
D)  They hydrogen bond extensively with each other.

Question 7

Proline exists in the cis configuration more frequently than any other amino acid.

Accepted Answer

A) True 
 B)False

Question 8

What would you expect about the formation of an α-helix for a segment of a protein chain that contains lysine approximately every fourth residue with all other residues being mostly hydrophobic?

Accepted Answer

A)  Helix formation would be favored at low pH. 
B)  Helix formation would be favored at high pH. 
C)  Helix formation would be favored at neutral pH. 
D)  Helix formation would never occur regardless of pH. 
A)  Helix formation would be favored at low pH. 
B)  Helix formation would be favored at high pH. 
C)  Helix formation would be favored at neutral pH. 
D)  Helix formation would never occur regardless of pH.

Question 9

A tetrameric protein contains

Accepted Answer

A)  four different subunits. 
B)  four identical subunits. 
C)  three subunits and one prosthetic group. 
D)  A or B only 
E)  A, B or C 
A)  four different subunits. 
B)  four identical subunits. 
C)  three subunits and one prosthetic group. 
D)  A or B only 
E)  A, B or C

Question 10

The native structures of proteins are more stable than non-native conformations; they occupy a low-energy well when folded.

Accepted Answer

A) True 
 B)False

Question 11

How many monomers are there in an oligomeric protein designated αβ2γ2?

Accepted Answer

A)  2 
B)  3 
C)  4 
D)  5 
E)  not given 
A)  2 
B)  3 
C)  4 
D)  5 
E)  not given

Question 12

Cooperative binding of oxygen by hemoglobin

Accepted Answer

A)  is induced by hemoglobin. 
B)  is a result of different affinities for oxygen by each subunit protein. 
C)  is induced by oxygenation. 
D)  is a result of interaction with myoglobin. 
A)  is induced by hemoglobin. 
B)  is a result of different affinities for oxygen by each subunit protein. 
C)  is induced by oxygenation. 
D)  is a result of interaction with myoglobin.

Question 13

Protein folding can be followed in the laboratory by measuring

Accepted Answer

A)  viscosity. 
B)  electrophoretic mobility and gel filtration. 
C)  UV absorption and light rotation. 
D)  A, B, and C above 
E)  A and C above 
A)  viscosity. 
B)  electrophoretic mobility and gel filtration. 
C)  UV absorption and light rotation. 
D)  A, B, and C above 
E)  A and C above

Question 14

What does it mean to say a protein is oligomeric?

Accepted Answer

A)  In vivo it establishes an equilibrium between two or more active conformations. 
B)  It has more than fifty amino acids. 
C)  The active protein involves the association of two or more polypeptide chains. 
D)  The protein has multiple α-helices. 
A)  In vivo it establishes an equilibrium between two or more active conformations. 
B)  It has more than fifty amino acids. 
C)  The active protein involves the association of two or more polypeptide chains. 
D)  The protein has multiple α-helices.

Question 15

Which was a major scientific accomplishment by Linus Pauling?

Accepted Answer

A)  Determined the α-helix structure in keratin. 
B)  Discovered β-strands and described their assembly into sheets. 
C)  Determined the three-dimensional structure of hemoglobin and myoglobin. 
D)  Determined the structure of penicillin. 
A)  Determined the α-helix structure in keratin. 
B)  Discovered β-strands and described their assembly into sheets. 
C)  Determined the three-dimensional structure of hemoglobin and myoglobin. 
D)  Determined the structure of penicillin.

Question 16

α-helices easily form on the surface of water-soluble proteins due to the stabilizing effect of hydrogen bonding with water.

Accepted Answer

A) True 
 B)False

Question 17

Which is not true about β-sheets?

Accepted Answer

A)  The side-chains of all amino acids point to the same side of the sheet. 
B)  The polypeptide chains in the sheet are nearly fully extended. 
C)  The range of allowed phi and psi angles is broader than for those in the α-helix. 
D)  In antiparallel sheets the hydrogen bonds between adjacent strands are nearly perpendicular to the backbones of the strands. 
A)  The side-chains of all amino acids point to the same side of the sheet. 
B)  The polypeptide chains in the sheet are nearly fully extended. 
C)  The range of allowed phi and psi angles is broader than for those in the α-helix. 
D)  In antiparallel sheets the hydrogen bonds between adjacent strands are nearly perpendicular to the backbones of the strands.

Question 18

Match the protein organization most associated with the terms) listed below: A) Tertiary
B) Secondary
C) Primary
D) Quaternary
-Peptide bonds

Accepted Answer

The answer of Match the protein organization most associated with...

Question 19

Heat shock proteins are those stable at higher temperatures.

Accepted Answer

A) True 
 B)False

Question 20

Ascorbic acid is necessary for the formation of hydroxyproline and hydroxylysine residues before they are incorporated into the collagen protein molecule.

Accepted Answer

A) True 
 B)False

Exam 4: Proteins: Three-Dimensional Structure and Function

Which represents the backbone of a protein? Note: R = amino acid side chain N = nitrogen Cα = alpha carbon C = carbonyl carbon

Match the protein organization most associated with the terms) listed below: A) Tertiary B) Secondary C) Primary D) Quaternary -Hydrogen bonds between carbonyl and amino groups

Chaperones are proteins which

The main property of myoglobin and hemoglobin that makes them an efficient system for oxygen delivery from lungs to muscles is

The principle forces holding subunits of an oligomeric protein to each other are .

Which is true about the side chains of residues in an α-helix?

Proline exists in the cis configuration more frequently than any other amino acid.

What would you expect about the formation of an α-helix for a segment of a protein chain that contains lysine approximately every fourth residue with all other residues being mostly hydrophobic?

A tetrameric protein contains

The native structures of proteins are more stable than non-native conformations; they occupy a low-energy well when folded.

How many monomers are there in an oligomeric protein designated αβ2γ2?

Cooperative binding of oxygen by hemoglobin

Protein folding can be followed in the laboratory by measuring

What does it mean to say a protein is oligomeric?

Which was a major scientific accomplishment by Linus Pauling?

α-helices easily form on the surface of water-soluble proteins due to the stabilizing effect of hydrogen bonding with water.

Which is not true about β-sheets?

Match the protein organization most associated with the terms) listed below: A) Tertiary B) Secondary C) Primary D) Quaternary -Peptide bonds

Heat shock proteins are those stable at higher temperatures.

Ascorbic acid is necessary for the formation of hydroxyproline and hydroxylysine residues before they are incorporated into the collagen protein molecule.

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 Oxidative Phosphorylation

Photosynthesis

Lipid Metabolism

Amino Acid Metabolism

Nucleotide Metabolism

Nucleic Acids

Dna Replication, Repair, and Recombination

Transcription and Rna Processing

Protein Synthesis

Recombinant Dna Technology

Filters

Which represents the backbone of a protein? Note: R = amino acid side chain N = nitrogen C_α= alpha carbon C = carbonyl carbon

How many monomers are there in an oligomeric protein designated αβ₂γ₂?