Question 1

In a protein, the most conformationally restricted amino acid is ______; the least conformationally restricted is ______.

Accepted Answer

A) Trp, Gly 
B) Met, Cys 
C) Pro, Gly 
D) Ile, Ala 
E) Ala, Pro 
A) Trp, Gly 
B) Met, Cys 
C) Pro, Gly 
D) Ile, Ala 
E) Ala, Pro C

Question 2

Which of the following structural proteins has the greatest elasticity?

Accepted Answer

A) ($\alpha$keratin) 
B) β ketatin 
C) collagen 
D) pleated collagen 
E) A and B are equal 
A) ($\alpha$keratin) 
B) β ketatin 
C) collagen 
D) pleated collagen 
E) A and B are equal D

Question 3

Which statement below does not describe fibrous proteins?

Accepted Answer

A) Domains have a globular fold. 
B) These proteins usually contain only one type of secondary structure. 
C) These proteins usually exhibit structural or protective characteristics. 
D) These proteins have usually elongated hydrophilic surfaces. 
E) These proteins are usually insoluble in water. 
A) Domains have a globular fold. 
B) These proteins usually contain only one type of secondary structure. 
C) These proteins usually exhibit structural or protective characteristics. 
D) These proteins have usually elongated hydrophilic surfaces. 
E) These proteins are usually insoluble in water. A

Question 4

Matching
-The overall arrangement of the regular structural elements such as the α helix and the β sheet in the protein are considered the protein's ______.

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 5

Matching
-A rigid, planar structure between at least two amino acids consisting of about 40% double bond character is characteristic of a ______.

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 6

The Protein Data Bank (PDB)is a database provides structural information about proteins that may be useful for which of the following?
I.A researcher studying the changes in protein fold associated with prions.
II.A researcher classifying structural elements by function.
III A researcher designing a compound to bind tightly to a particular region in the protein.

Accepted Answer

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

Question 7

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 8

Which of the following amino acids combinations have side chains with groups that have the greatest ability to stabilize the tertiary structure of a protein?

Accepted Answer

A) Lys and Arg 
B) Cys and Glu 
C) Glu and Lys 
D) Gln and Glu 
E) Pro and Asp 
A) Lys and Arg 
B) Cys and Glu 
C) Glu and Lys 
D) Gln and Glu 
E) Pro and Asp

Question 9

Which of the following best describes the cause of Creutzfeld-Jakob Disease (a disease which human can develop with symptoms similar to those of mad cow disease)?

Accepted Answer

A) aggregation of a misfolded protein. 
B) aggregation of random coil regions on a protein. 
C) ingestion of ammonium salts. 
D) the serious side effects of experimental treatment with Quinacrine 
E) All are potential causes Creutzfeld-Jakob disease. 
A) aggregation of a misfolded protein. 
B) aggregation of random coil regions on a protein. 
C) ingestion of ammonium salts. 
D) the serious side effects of experimental treatment with Quinacrine 
E) All are potential causes Creutzfeld-Jakob disease.

Question 10

Of the following, which amino acid is most likely to be found in position 1 or 4 on α keratin?

Accepted Answer

A) Phe 
B) Ala 
C) Lys 
D) Trp 
E) Pro 
A) Phe 
B) Ala 
C) Lys 
D) Trp 
E) Pro

Question 11

What observation about protein refolding or renaturation helped to solidify the connection between primary amino acid sequence and 3-D structure?

Accepted Answer

A) Spontaneous refolding of proteins into their native state under physiologic conditions. 
B) Assisted refolding of proteins into their native state under laboratory conditions. 
C) Identification of thermostable proteins than maintain their native state in adverse temperatures. 
D) A and B 
E) B and C 
A) Spontaneous refolding of proteins into their native state under physiologic conditions. 
B) Assisted refolding of proteins into their native state under laboratory conditions. 
C) Identification of thermostable proteins than maintain their native state in adverse temperatures. 
D) A and B 
E) B and C

Question 12

Matching
-The strength of _______ comes from close packing of glycine residues and the characteristics of hydroxyproline allowing formation of a left- handed helical conformation which combines with two other left handed structures to form a right-handed triplet helix.

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 13

The low pH found in the gut can enhance the digestibility of dietary protein by causing ___.

Accepted Answer

A) amide hydrolysis 
B) protein denaturation 
C) disulfide reduction 
D) prion formation 
E) cysteine oxidation 
A) amide hydrolysis 
B) protein denaturation 
C) disulfide reduction 
D) prion formation 
E) cysteine oxidation

Question 14

Which of the following is true regarding crystalline proteins?

Accepted Answer

A) Many crystallized enzyme proteins remain catalytically active. 
B) The diffractive pattern observed during X-ray exposure to the crystal can be used to calculate the electron density map of the crystalline protein. 
C) The larger region indicating electron density with in the electron density map, the more accurate the structure determination. 
D) A and B are true. 
E) A, B, and C are true. 
A) Many crystallized enzyme proteins remain catalytically active. 
B) The diffractive pattern observed during X-ray exposure to the crystal can be used to calculate the electron density map of the crystalline protein. 
C) The larger region indicating electron density with in the electron density map, the more accurate the structure determination. 
D) A and B are true. 
E) A, B, and C are true.

Question 15

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 16

Matching
-Repeating values of $\varPhi$and $\varPsi$ make up predictable orientations of amino acid with a chain, this predictable orientation forms___________.

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 17

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 18

Matching
-A historical experiment exploring denaturation upon β- mercaptoethanol reduction of disulfide bonds and spontaneous renaturation upon dialysis to remove the β- mercaptoethanol was carried out using the protein ______.This experiment demonstrated the importance of disulfide bonds and amino acid sequence in folding of proteins.

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 19

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 20

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.

Exam 6: Proteins: Three-Dimensional Structure

In a protein, the most conformationally restricted amino acid is ______; the least conformationally restricted is ______.

Which of the following structural proteins has the greatest elasticity?

Which statement below does not describe fibrous proteins?

Matching -The overall arrangement of the regular structural elements such as the α helix and the β sheet in the protein are considered the protein's ______.

Matching -A rigid, planar structure between at least two amino acids consisting of about 40% double bond character is characteristic of a ______.

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

Which of the following amino acids combinations have side chains with groups that have the greatest ability to stabilize the tertiary structure of a protein?

Which of the following best describes the cause of Creutzfeld-Jakob Disease (a disease which human can develop with symptoms similar to those of mad cow disease)?

Of the following, which amino acid is most likely to be found in position 1 or 4 on α keratin?

What observation about protein refolding or renaturation helped to solidify the connection between primary amino acid sequence and 3-D structure?

Matching -The strength of _______ comes from close packing of glycine residues and the characteristics of hydroxyproline allowing formation of a left- handed helical conformation which combines with two other left handed structures to form a right-handed triplet helix.

The low pH found in the gut can enhance the digestibility of dietary protein by causing ___.

Which of the following is true regarding crystalline proteins?

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

Matching -Repeating values of Φ\varPhiΦ and Ψ\varPsiΨ make up predictable orientations of amino acid with a chain, this predictable orientation forms___________.

Protein diseases can be caused by which of the following

Which of the following statements is true regarding collagen?

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

Glycogen Metabolism and Gluconeogenesis

Glucose Catabolism

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

Translation

Regulation of Gene Expression

Filters

In a protein, the most conformationally restricted amino acid is ; the least conformationally restricted is .

Matching -Repeating values of $\varPhi$ and $\varPsi$ make up predictable orientations of amino acid with a chain, this predictable orientation forms___________.