Question 1

Protein diseases can be caused by which of the following

Accepted Answer

A) mutations affecting the 1° structure. 
B) mutations affecting the 3° structure. 
C) changes in the post-synthetic processing of proteins. 
D) All of the above are potential causes. 
E) None of the above are potential causes. 
A) mutations affecting the 1° structure. 
B) mutations affecting the 3° structure. 
C) changes in the post-synthetic processing of proteins. 
D) All of the above are potential causes. 
E) None of the above are potential causes.

Question 2

Evolutionary processes have

Accepted Answer

A) increased the stability of 4° structures. 
B) decreased the number of subunits. 
C) increased similarity amount 1° structures. 
D) enhanced efficient folding pathways. 
E) all of the above 
A) increased the stability of 4° structures. 
B) decreased the number of subunits. 
C) increased similarity amount 1° structures. 
D) enhanced efficient folding pathways. 
E) all of the above

Question 3

For $\beta$-sheets,the terms 'parallel' and 'antiparalllel' refer to ___________.

Accepted Answer

A) the 'direction' of the associated peptide strands 
B) the orientation of the amide cross-links 
C) the quaternary structure of the protein 
D) the orientation of the hydrogen bonding 
E) the topology of the reverse turns 
A) the 'direction' of the associated peptide strands 
B) the orientation of the amide cross-links 
C) the quaternary structure of the protein 
D) the orientation of the hydrogen bonding 
E) the topology of the reverse turns

Question 4

Which of the following occurs first when folding a disordered polypeptide chain into a stable protein formation?

Accepted Answer

A) formation of a low energy state 
B) association of ordered subunits 
C) aggregation of hydrophobic regions in the protein 
D) tertiary structure refinement 
E) formation of a low entropy state 
A) formation of a low energy state 
B) association of ordered subunits 
C) aggregation of hydrophobic regions in the protein 
D) tertiary structure refinement 
E) formation of a low entropy state

Question 5

The structure and sequence of a protein of unknown function was examined.Which of the following provides the best prediction of the protein's function?

Accepted Answer

A) the observation of several disordered α helical domains. 
B) the observation of multiple protein subunits. 
C) the observation of motif known as the Rossmann fold. 
D) the observation of a large number of random coil regions. 
E) All of the above offer excellent prediction of the protein's function. 
A) the observation of several disordered α helical domains. 
B) the observation of multiple protein subunits. 
C) the observation of motif known as the Rossmann fold. 
D) the observation of a large number of random coil regions. 
E) All of the above offer excellent prediction of the protein's function.

Question 6

Noncovalent interactions account for the strength of which of the following structural proteins?

Accepted Answer

A) "$\alpha$ keratin" 
B) "collagen" 
C) "pleated collagen" 
D) "A and B" 
E) "B and C" 
A) "$\alpha$ keratin" 
B) "collagen" 
C) "pleated collagen" 
D) "A and B" 
E) "B and C"

Question 7

Hydrogen bonds and maximum separation of amino acid side chains make the _____very stable and energetically ______________.

Accepted Answer

A) α helix and β sheet,favorable 
B) α helix,unfavorable 
C) β sheet,unfavorable 
D) α helix,favorable 
E) β sheet,favorable 
A) α helix and β sheet,favorable 
B) α helix,unfavorable 
C) β sheet,unfavorable 
D) α helix,favorable 
E) β sheet,favorable

Question 8

In the absence of ascorbic acid,prolyl oxidase is unable to oxidize proline residues in collagen to hydroxyproline,resulting in:

Accepted Answer

A) lathyrism 
B) prion diseases 
C) amyloid formation 
D) scurvy 
E) allysine 
A) lathyrism 
B) prion diseases 
C) amyloid formation 
D) scurvy 
E) allysine

Question 9

When considering fibrous proteins,which of the following statements is TRUE?

Accepted Answer

A) Noncovalent interactions contribute to the strength of all of these proteins. 
B) All of them consist of $\alpha$ helix structure. 
C) All of them require vitamin C. 
D) Decrease in amounts of any of them cause scurvy. 
E) All of these are true of fibrous proteins. 
A) Noncovalent interactions contribute to the strength of all of these proteins. 
B) All of them consist of $\alpha$ helix structure. 
C) All of them require vitamin C. 
D) Decrease in amounts of any of them cause scurvy. 
E) All of these are true of fibrous proteins.

Question 10

Matching

-In most peptide groups the ______ conformation is not sterically favored.

Accepted Answer

A)  tertiary structure 
B)  keratin 
C)  molecular chaperones 
D)  hydropathy 
E)  cis
F) trans
G) sterically forbidden conformation 
H) regular secondary structure
I) collagen
J) peptide  bond
K) ribonuclease A (RNase 
A) 
L) alpha 
A)  tertiary structure 
B)  keratin 
C)  molecular chaperones 
D)  hydropathy 
E)  cis
F) trans
G) sterically forbidden conformation 
H) regular secondary structure
I) collagen
J) peptide  bond
K) ribonuclease A (RNase 
A) 
L) alpha

Question 11

A chaperonin

Accepted Answer

A) helps fold some proteins in their lowest energy state. 
B) is required for all proteins to fold properly. 
C) mediates the unfolding of proteins. 
D) is required for protein denaturation. 
E) counteracts the laws of thermodynamics. 
A) helps fold some proteins in their lowest energy state. 
B) is required for all proteins to fold properly. 
C) mediates the unfolding of proteins. 
D) is required for protein denaturation. 
E) counteracts the laws of thermodynamics.

Question 12

Which one of these characteristics is not true for the $\alpha$ helix?

Accepted Answer

A) There are 3.6 amino acids per turn. 
B) There is a requirement for glycine every third amino acid residue. 
C) A hydrogen bond forms between the carbonyl oxygen of the nth amino acid residue and the - NH group of the (n + 4)th amino acid residue. 
D) Proline is typically not found in the $\alpha$ helix. 
E) It is right-handed. 
A) There are 3.6 amino acids per turn. 
B) There is a requirement for glycine every third amino acid residue. 
C) A hydrogen bond forms between the carbonyl oxygen of the nth amino acid residue and the - NH group of the (n + 4)th amino acid residue. 
D) Proline is typically not found in the $\alpha$ helix. 
E) It is right-handed.

Question 13

Which of the following statements is true regarding collagen?

Accepted Answer

A) The inability to hydroxylate proline results in the inability to synthesize collagen. 
B) The α helical structure is ideal for intertwining 3 filaments. 
C) Hydrogen bonds between the ─OH groups of Hyp residues stabilize the helix. 
D) The requirement for glycine every 3rd amino acid is essential for the triplet helix formation. 
E) On average,there is one proline for every hydroxyproline. 
A) The inability to hydroxylate proline results in the inability to synthesize collagen. 
B) The α helical structure is ideal for intertwining 3 filaments. 
C) Hydrogen bonds between the ─OH groups of Hyp residues stabilize the helix. 
D) The requirement for glycine every 3rd amino acid is essential for the triplet helix formation. 
E) On average,there is one proline for every hydroxyproline.

Question 14

Molecular chaperones bind to unfolded or partially folded polypeptide chains in order to accomplish which of the following?

Accepted Answer

A) ensure that improper aggregation of hydrophobic segments does not occur 
B) engulf the protein in order to ensure that the protein is not damaged by heat denaturation 
C) facilitate native folding by exposing hydrophobic segments of the protein as it is synthesized 
D) facilitate aggregation of multiple subunits of a protein during synthesis 
E) All of the above are accomplished by molecular chaperones. 
A) ensure that improper aggregation of hydrophobic segments does not occur 
B) engulf the protein in order to ensure that the protein is not damaged by heat denaturation 
C) facilitate native folding by exposing hydrophobic segments of the protein as it is synthesized 
D) facilitate aggregation of multiple subunits of a protein during synthesis 
E) All of the above are accomplished by molecular chaperones.

Question 15

Imagine that a researcher treated a protein with a high concentration of a chaotropic agent.Which of the following is the most likely result of the treatment?
(I)Nonpolar portions of the protein become more soluble.
(II)The protein begins to denature ,
(III)The protein stability increases due to hydrophobic collapse,

Accepted Answer

A) I,II,III 
B) I,II 
C) II,III 
D) I,III 
E) II 
A) I,II,III 
B) I,II 
C) II,III 
D) I,III 
E) II

Question 16

In general molecular chaperone proteins function by

Accepted Answer

A) mediating disulfide bond formation 
B) synthesizing new proteins when one is misfolded. 
C) preventing premature folding by binding hydrophobic regions of the protein. 
D) enhancing salt bridge formation. 
E) none of the above 
A) mediating disulfide bond formation 
B) synthesizing new proteins when one is misfolded. 
C) preventing premature folding by binding hydrophobic regions of the protein. 
D) enhancing salt bridge formation. 
E) none of the above

Question 17

Native protein purifications often require multiple reaction steps in order to purify the protein of interest from other proteins.One method used for protein separation in purification procedures is a change from water to an organic solvent.Which of the following would be accomplished by this solvent change?

Accepted Answer

A) Proteins with hydrophobic groups on the interior would maintain their native state. 
B) Proteins with hydrophilic groups on the exterior would denature and likely precipitate. 
C) Proteins with exposed hydrophobic groups would maintain their structure and remain in solution. 
D) Both A and B would occur. 
E) Both B and C would occur. 
A) Proteins with hydrophobic groups on the interior would maintain their native state. 
B) Proteins with hydrophilic groups on the exterior would denature and likely precipitate. 
C) Proteins with exposed hydrophobic groups would maintain their structure and remain in solution. 
D) Both A and B would occur. 
E) Both B and C would occur.

Question 18

The classic experiment demonstrating that reduced and denatured RNase A could refold into the native form demonstrates that _______.

Accepted Answer

A) 1° structure can determine 3° structure 
B) denaturation does not disrupt protein 2° structure 
C) disulfide bonds do not stabilize folded proteins 
D) All of the above. 
E) None of the above 
A) 1° structure can determine 3° structure 
B) denaturation does not disrupt protein 2° structure 
C) disulfide bonds do not stabilize folded proteins 
D) All of the above. 
E) None of the above

Question 19

A helix has hydrogen bonds between the carbonyl group from residue "n" and the amino group of residue "n+6," which of the following is TRUE?

Accepted Answer

A) It has 3.6 residues per turn. 
B) It is a random coil,not a helix. 
C) It is an α helix. 
D) It has more residues per turn than an α helix. 
E) It has fewer residues per turn than an α helix. 
A) It has 3.6 residues per turn. 
B) It is a random coil,not a helix. 
C) It is an α helix. 
D) It has more residues per turn than an α helix. 
E) It has fewer residues per turn than an α helix.

Question 20

Which of the following contribute to the minimization of energy that occurs with protein folding?

Accepted Answer

A) orientating amino acid groups to maximize hydrogen bonding 
B) folding hydrophobic groups towards the exterior of the protein 
C) burying polar groups towards the interior of the protein 
D) extensive cavity formation 
E) all of the above 
A) orientating amino acid groups to maximize hydrogen bonding 
B) folding hydrophobic groups towards the exterior of the protein 
C) burying polar groups towards the interior of the protein 
D) extensive cavity formation 
E) all of the above

Exam 6: Proteins: Three-Dimensional Structure

Protein diseases can be caused by which of the following

Evolutionary processes have

For β\betaβ -sheets,the terms 'parallel' and 'antiparalllel' refer to ___________.

Which of the following occurs first when folding a disordered polypeptide chain into a stable protein formation?

The structure and sequence of a protein of unknown function was examined.Which of the following provides the best prediction of the protein's function?

Noncovalent interactions account for the strength of which of the following structural proteins?

Hydrogen bonds and maximum separation of amino acid side chains make the _____very stable and energetically ______________.

In the absence of ascorbic acid,prolyl oxidase is unable to oxidize proline residues in collagen to hydroxyproline,resulting in:

When considering fibrous proteins,which of the following statements is TRUE?

Matching -In most peptide groups the ______ conformation is not sterically favored.

A chaperonin

Which one of these characteristics is not true for the α\alphaα helix?

Which of the following statements is true regarding collagen?

Molecular chaperones bind to unfolded or partially folded polypeptide chains in order to accomplish which of the following?

In general molecular chaperone proteins function by

The classic experiment demonstrating that reduced and denatured RNase A could refold into the native form demonstrates that _______.

A helix has hydrogen bonds between the carbonyl group from residue "n" and the amino group of residue "n+6," which of the following is TRUE?

Which of the following contribute to the minimization of energy that occurs with protein folding?

Introduction to the Chemistry of Life

Water

Nucleotides, nucleic Acids, and Genetic Information

Amino Acids

Proteins: Primary Structure

Protein Function Part I: Myoglobin and Hemoglobin

Carbohydrates

Lipids and Biological Membranes

Membrane Transport

Enzyme Catalysis

Enzyme Kinetics, inhibition and Control

Biochemical Signaling

Introduction to Metabolism

Glucose Catabolism

Glycogen Metabolism and Gluconeogenesis

Citric Acid Cycle

Electron Transport and Oxidative Phosphorylation

Photosynthesis

Lipid Metabolism

Amino Acid Metabolism

Mammalian Fuel Metabolism: Integration and Regulation

Nucleotide Metabolism

Nucleic Acid Structure

DNA Replication, repair and Recombination

Transcription and Rna Processing

Protein Synthesis

Regulation of Gene Expression

Filters

For $\beta$ -sheets,the terms 'parallel' and 'antiparalllel' refer to ___________.

Hydrogen bonds and maximum separation of amino acid side chains make the _very stable and energetically __________.

Which one of these characteristics is not true for the $\alpha$ helix?