Question 1

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

Accepted Answer

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

Question 2

To what level of structure do α-helices belong?

Accepted Answer

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

Question 3

Nearly all peptide bonds are in the trans configuration because

Accepted Answer

A) cis peptide bonds are weaker. 
B) trans peptide bonds are stronger. 
C) cis peptide bonds prevent R groups from interacting. 
D) trans peptide bonds minimize steric hindrance of R groups. 
A) cis peptide bonds are weaker. 
B) trans peptide bonds are stronger. 
C) cis peptide bonds prevent R groups from interacting. 
D) trans peptide bonds minimize steric hindrance of R groups. D

Question 4

Proteins with alpha helix regions called leucine zippers are

Accepted Answer

A) often found in DNA binding proteins. 
B) amphipathic helices. 
C) part of pairs of helices that are wrapped around each other. 
D) All of the above. 
A) often found in DNA binding proteins. 
B) amphipathic helices. 
C) part of pairs of helices that are wrapped around each other. 
D) All of the above.

Question 5

The Tm of a protein is temperature at which it

Accepted Answer

A) is completely denatured. 
B) liquifies. 
C) is half denatured. 
D) resists denaturation. 
A) is completely denatured. 
B) liquifies. 
C) is half denatured. 
D) resists denaturation.

Question 6

What is true about the rotation about bonds in a protein backbone?

Accepted Answer

A) The rotation is free about all bonds in the backbone,except for the bond between the nitrogen and the alpha carbon in proline residues. 
B) The bond between the carbonyl carbon and nitrogen is restricted.Other bonds are free to rotate depending only on steric hindrance or the presence of proline residues. 
C) All bonds in the backbone have restricted rotation and partial double-bond character. 
D) The rotation is free only about the peptide bond.The other bonds are restricted by steric hindrance and the presence of proline residues. 
A) The rotation is free about all bonds in the backbone,except for the bond between the nitrogen and the alpha carbon in proline residues. 
B) The bond between the carbonyl carbon and nitrogen is restricted.Other bonds are free to rotate depending only on steric hindrance or the presence of proline residues. 
C) All bonds in the backbone have restricted rotation and partial double-bond character. 
D) The rotation is free only about the peptide bond.The other bonds are restricted by steric hindrance and the presence of proline residues.

Question 7

Which is a reasonable number of different polypeptides found in humans?

Accepted Answer

A) 2000 
B) 20,000 
C) 2,000,000 
D) 2,000,000,000 
A) 2000 
B) 20,000 
C) 2,000,000 
D) 2,000,000,000

Question 8

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 9

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 10

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 11

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 12

In addition to self assembly,some proteins fold with the help of

Accepted Answer

A) energy stabilizers. 
B) weak chemical interactions. 
C) other proteins. 
D) low entropy pickets. 
E) All of the above. 
A) energy stabilizers. 
B) weak chemical interactions. 
C) other proteins. 
D) low entropy pickets. 
E) All of the above.

Question 13

For each term select the description that best describes its contribution to the structure of collagen.
-Hydroxyproline

Accepted Answer

A) Forms covalent cross links 
B) Makes the protein rigid 
C) Required for hydroxylation 
D) Allows tightly wound helix formation 
E) Has H bonds which help stabilize the protein 
A) Forms covalent cross links 
B) Makes the protein rigid 
C) Required for hydroxylation 
D) Allows tightly wound helix formation 
E) Has H bonds which help stabilize the protein

Question 14

Part of immunoglobulin molecules can be changed in order to bind to a variety of antigens while the amino acid sequence of another part does not change.

Accepted Answer

A) True 
 B)False

Question 15

Match each level of organization with a description.
-Tertiary 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 16

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 17

All proteins possess primary,secondary,tertiary and quaternary structure.

Accepted Answer

A) True 
 B)False

Question 18

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

Accepted Answer

A) True 
 B)False

Question 19

Antibodies are suitable for diagnostic tests because

Accepted Answer

A) they can be made radioactive. 
B) they can be readily purified. 
C) they are found in very small quantities. 
D) they bind very specifically to antigens. 
E) they are found everywhere. 
A) they can be made radioactive. 
B) they can be readily purified. 
C) they are found in very small quantities. 
D) they bind very specifically to antigens. 
E) they are found everywhere.

Question 20

Tertiary structure of proteins describe

Accepted Answer

A) polypeptide folding. 
B) bringing amino acids far apart in primary structure close together. 
C) stabilizing protein structure by non-covalent interaction. 
D) disulfide bridges. 
E) All of the above. 
A) polypeptide folding. 
B) bringing amino acids far apart in primary structure close together. 
C) stabilizing protein structure by non-covalent interaction. 
D) disulfide bridges. 
E) All of the above.

Exam 4: Proteins: Three-Dimensional Structure and Function

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

To what level of structure do α-helices belong?

Nearly all peptide bonds are in the trans configuration because

Proteins with alpha helix regions called leucine zippers are

The Tm of a protein is temperature at which it

What is true about the rotation about bonds in a protein backbone?

Which is a reasonable number of different polypeptides found in humans?

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

What does it mean to say a protein is oligomeric?

Which was a major scientific accomplishment by Linus Pauling?

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?

In addition to self assembly,some proteins fold with the help of

For each term select the description that best describes its contribution to the structure of collagen. -Hydroxyproline

Part of immunoglobulin molecules can be changed in order to bind to a variety of antigens while the amino acid sequence of another part does not change.

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

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

All proteins possess primary,secondary,tertiary and quaternary structure.

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

Antibodies are suitable for diagnostic tests because

Tertiary structure of proteins describe

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

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