Question 1

All are structural and functional advantages to quaternary structure EXCEPT:

Accepted Answer

A)  cooperativity. 
B)  stability. 
C)  bringing catalytic sites together. 
D)  genetic economy and efficiency. 
E)  all are true. 
A)  cooperativity. 
B)  stability. 
C)  bringing catalytic sites together. 
D)  genetic economy and efficiency. 
E)  all are true. E

Question 2

A hydrophobic interaction might occur within a protein between which of the following amino acid pairs?

Accepted Answer

A)  Ser/Ile 
B)  Val/Leu 
C)  Tyr/Cys 
D)  Lys/Asn 
E)  His/Val 
A)  Ser/Ile 
B)  Val/Leu 
C)  Tyr/Cys 
D)  Lys/Asn 
E)  His/Val B

Question 3

An electrostatic interaction might occur within a protein between which of the following amino acid pairs at typical physiological pH?

Accepted Answer

A)  Ser/Asn 
B)  Asp/Glu 
C)  Arg/Cys 
D)  Lys/Asp 
E)  Val/Ile 
A)  Ser/Asn 
B)  Asp/Glu 
C)  Arg/Cys 
D)  Lys/Asp 
E)  Val/Ile D

Question 4

Which statement is correct about the β−α−β motif?

Accepted Answer

A)  The two β-strands are antiparellel. 
B)  The peptide segment connecting the β-strands usually contains no more than five amino acids. 
C)  The peptide segment connecting the two β-strands commonly contains proline. 
D)  The cross-over connection itself contains an α-helical segment. 
E)  none are correct. 
A)  The two β-strands are antiparellel. 
B)  The peptide segment connecting the β-strands usually contains no more than five amino acids. 
C)  The peptide segment connecting the two β-strands commonly contains proline. 
D)  The cross-over connection itself contains an α-helical segment. 
E)  none are correct.

Question 5

Which of the following would be the most rapidly occurring event giving rise to protein motion?

Accepted Answer

A)  hinge-bending movement between protein domains 
B)  tyrosine ring flip 
C)  cis-trans isomerization of proline 
D)  protein conformational change 
E)  both b and c are equally rapid 
A)  hinge-bending movement between protein domains 
B)  tyrosine ring flip 
C)  cis-trans isomerization of proline 
D)  protein conformational change 
E)  both b and c are equally rapid

Question 6

If an aspartic acid residue were present in the interior of a globular protein, it would most likely be _________.

Accepted Answer

A)  deprotonated and thus negatively charged 
B)  tightly associated with the R-group of a lysine residue 
C)  react with a cysteine to form a thioester 
D)  react with a serine to form an ester 
E)  none of the above 
A)  deprotonated and thus negatively charged 
B)  tightly associated with the R-group of a lysine residue 
C)  react with a cysteine to form a thioester 
D)  react with a serine to form an ester 
E)  none of the above

Question 7

β-Turns in a peptide chain form a tight loop with hydrogen bonding of the carbonyl oxygen with:

Accepted Answer

A)  side chain amine of lysine two amino acids down the chain. 
B)  amide proton on the next amino acid down the chain. 
C)  amide proton of the glutamine side chain. 
D)  amide proton of the residue three positions down the chain. 
E)  amide proton of asparagine side chain. 
A)  side chain amine of lysine two amino acids down the chain. 
B)  amide proton on the next amino acid down the chain. 
C)  amide proton of the glutamine side chain. 
D)  amide proton of the residue three positions down the chain. 
E)  amide proton of asparagine side chain.

Question 8

Explain the role of hydrophobic interactions in protein folding.​

Accepted Answer

Hydrophobic "bonds," or, more accurately

Question 9

Discuss cooperativity in proteins.​

Accepted Answer

Multisubunit proteins typically possess

Question 10

Arrange the steps involved in folding of globular proteins into a proper sequencE.
A."Molten globule" formation of assembled domains.
B.Formation of domains through cooperative aggregation of folding nuclei.
C.Adjustment in the conformation of domains.
D.Rapid and reversible formation of local secondary structurE.E.Final protein monomer formation.

Accepted Answer

A)  A, B, C, D, E. 
B)  B, C, E, A, D 
C)  D, C, B, A, E 
D)  D, B, A, C, E 
E)  B, D, C, A, E 
A)  A, B, C, D, E. 
B)  B, C, E, A, D 
C)  D, C, B, A, E 
D)  D, B, A, C, E 
E)  B, D, C, A, E

Question 11

Fibrous proteins contain polypeptide chains ____ producing long fibers or large sheets.

Accepted Answer

A)  with an abundance of aromatic amino acids 
B)  with an abundance of hydrophilic amino acids 
C)  organized approximately parallel along a single axis 
D)  with amino acids arranged in a repeating (-a-b-c-d-)n sequence 
E)  all are true 
A)  with an abundance of aromatic amino acids 
B)  with an abundance of hydrophilic amino acids 
C)  organized approximately parallel along a single axis 
D)  with amino acids arranged in a repeating (-a-b-c-d-)n sequence 
E)  all are true

Question 12

In the tertiary structure of a protein, an electrostatic interaction could form between the R-groups of which two amino acids?

Accepted Answer

A)  Gln and Lys 
B)  Asp and Thr 
C)  Leu and Asp 
D)  Glu and Arg 
E)  Arg and His 
A)  Gln and Lys 
B)  Asp and Thr 
C)  Leu and Asp 
D)  Glu and Arg 
E)  Arg and His

Question 13

____ between tightly packed amino acid side chains in the interior of the protein are a major contribution to protein structure.

Accepted Answer

A)  Hydrogen bonds 
B)  Electrostatic interactions 
C)  Covalent ester bonds 
D)  Van der Waals interactions 
E)  All are true 
A)  Hydrogen bonds 
B)  Electrostatic interactions 
C)  Covalent ester bonds 
D)  Van der Waals interactions 
E)  All are true

Question 14

Tertiary structure is defined as:

Accepted Answer

A)  the sequence of amino acids. 
B)  the folding of a single polypeptide chain in three-dimensional space. 
C)  hydrogen bonding interactions between adjacent amino acid residues into helical or pleated segments. 
D)  the way in which separate folded monomeric protein subunits associate to form oligomeric proteins. 
E)  all are true. 
A)  the sequence of amino acids. 
B)  the folding of a single polypeptide chain in three-dimensional space. 
C)  hydrogen bonding interactions between adjacent amino acid residues into helical or pleated segments. 
D)  the way in which separate folded monomeric protein subunits associate to form oligomeric proteins. 
E)  all are true.

Question 15

Why should the core of most globular and membrane proteins consist almost entirely of α-helix and β-sheets?

Accepted Answer

A)  Hydrogen bonded structures must be kept away from water solvent. 
B)  Highly polar N−H and C=O moieties of the peptide backbone must be neutralized in the hydrophobic core of the protein. 
C)  Hydrogen bonding only occurs in the core of proteins. 
D)  Trapped water stabilizes the helix and sheet structures. 
E)  None are true. 
A)  Hydrogen bonded structures must be kept away from water solvent. 
B)  Highly polar N−H and C=O moieties of the peptide backbone must be neutralized in the hydrophobic core of the protein. 
C)  Hydrogen bonding only occurs in the core of proteins. 
D)  Trapped water stabilizes the helix and sheet structures. 
E)  None are true.

Question 16

All of the statements about the tertiary structure of the enzyme triose phosphate isomerase are correct EXCEPT:

Accepted Answer

A)  Its β-strands are parallel. 
B)  Its α-helices are in the interior core of the molecular structure. 
C)  It contains a β-barrel in the center of its structure. 
D)  It is composed entirely of alternating α-helices and β-strands. 
E)  Hydrophobic residues are buried between concentric layers. 
A)  Its β-strands are parallel. 
B)  Its α-helices are in the interior core of the molecular structure. 
C)  It contains a β-barrel in the center of its structure. 
D)  It is composed entirely of alternating α-helices and β-strands. 
E)  Hydrophobic residues are buried between concentric layers.

Question 17

The amino acid residue most likely to be found in a beta turn is:

Accepted Answer

A)  glycine. 
B)  alanine. 
C)  valine. 
D)  glutamic acid. 
E)  leucine. 
A)  glycine. 
B)  alanine. 
C)  valine. 
D)  glutamic acid. 
E)  leucine.

Question 18

____ are examples of antiparallel α-helix proteins.

Accepted Answer

A)  Triose phosphate isomerase 
B)  Pyruvate kinase 
C)  Flavodoxin 
D)  Hemoglobin 
E)  Papain 
A)  Triose phosphate isomerase 
B)  Pyruvate kinase 
C)  Flavodoxin 
D)  Hemoglobin 
E)  Papain

Question 19

____ are proteins that help other proteins to fold.

Accepted Answer

A)  Immunoglobulins 
B)  Phospholipases 
C)  Synthetases 
D)  Molecular chaperones 
E)  Proteases 
A)  Immunoglobulins 
B)  Phospholipases 
C)  Synthetases 
D)  Molecular chaperones 
E)  Proteases

Question 20

____ amino acids are almost never found in the interior of a protein, but the protein surface may consist of ____ amino acids.

Accepted Answer

A)  Nonpolar, both polar and nonpolar 
B)  Nonpolar, mostly nonpolar 
C)  Polar, both polar and nonpolar 
D)  Polar, only polar 
E)  Polar, only nonpolar 
A)  Nonpolar, both polar and nonpolar 
B)  Nonpolar, mostly nonpolar 
C)  Polar, both polar and nonpolar 
D)  Polar, only polar 
E)  Polar, only nonpolar

Exam 6: Proteins: Secondary, Tertiary, and Quaternary Structure

All are structural and functional advantages to quaternary structure EXCEPT:

A hydrophobic interaction might occur within a protein between which of the following amino acid pairs?

An electrostatic interaction might occur within a protein between which of the following amino acid pairs at typical physiological pH?

Which statement is correct about the β−α−β motif?

Which of the following would be the most rapidly occurring event giving rise to protein motion?

If an aspartic acid residue were present in the interior of a globular protein, it would most likely be _________.

β-Turns in a peptide chain form a tight loop with hydrogen bonding of the carbonyl oxygen with:

Explain the role of hydrophobic interactions in protein folding.​

Discuss cooperativity in proteins.​

Fibrous proteins contain polypeptide chains ____ producing long fibers or large sheets.

In the tertiary structure of a protein, an electrostatic interaction could form between the R-groups of which two amino acids?

____ between tightly packed amino acid side chains in the interior of the protein are a major contribution to protein structure.

Tertiary structure is defined as:

Why should the core of most globular and membrane proteins consist almost entirely of α-helix and β-sheets?

All of the statements about the tertiary structure of the enzyme triose phosphate isomerase are correct EXCEPT:

The amino acid residue most likely to be found in a beta turn is:

____ are examples of antiparallel α-helix proteins.

____ are proteins that help other proteins to fold.

____ amino acids are almost never found in the interior of a protein, but the protein surface may consist of ____ amino acids.

The Facts of Life: Chemistry Is the Logic of Biological Phenomena

Water: the Medium of Life

Thermodynamics of Biological Systems

Amino Acids and the Peptide Bond

Proteins: Their Primary Structure and Biological Functions

Carbohydrates and the Glycoconjugates of Cell Surfaces

Lipids

Membranes and Membrane Transport

Nucleotides and Nucleic Acids

Structure of Nucleic Acids

Recombinant Dna, Cloning, Chimeric Genes, and Synthetic Biology

Enzymeskinetics and Specificity

Mechanisms of Enzyme Action

Enzyme Regulation

Molecular Motors

Metabolism: an Overview

Glycolysis

The Tricarboxylic Acid Cycle

Electron Transport and Oxidative Phosphorylation

Photosynthesis

Gluconeogenesis, Glycogen Metabolism, and the Pentose Phosphate Pathway

Fatty Acid Catabolism

Lipid Biosynthesis

Nitrogen Acquisition and Amino Acid Metabolism

Synthesis and Degradation of Nucleotides

Metabolic Integration and Organ Specialization

Dna Metabolism: Replication, Recombination, and Repair

Transcription and the Regulation of Gene Expression

Protein Synthesis

Completing the Protein Life Cycle: Folding, Processing, and Degradation

The Reception and Transmission of Extracellular Information

Filters

Explain the role of hydrophobic interactions in protein folding.

Discuss cooperativity in proteins.

amino acids are almost never found in the interior of a protein, but the protein surface may consist of amino acids.