Question 1

The is the single shape a protein adopts under physiological conditions.

Accepted Answer

A)  minimal configuration 
B)  native conformation 
C)  primary structure 
D)  most stable enantiomer 
A)  minimal configuration 
B)  native conformation 
C)  primary structure 
D)  most stable enantiomer

Question 2

The porphyrin prosthetic group is held into the interior of globin molecules by covalent bonds to specific amino acid residues.

Accepted Answer

A) True 
 B)False

Question 3

The subunits of a multisubunit proteins are always identical.

Accepted Answer

A) True 
 B)False

Question 4

Chaotropic agents denature by disrupting stabilizing hydrophobic interactions, while detergents denature by penetrating and disrupting hydrophilic interactions.

Accepted Answer

A) True 
 B)False

Question 5

is used to estimate the molecular weight of oligomeric proteins, while is used to determine molecular weight of each chain.

Accepted Answer

A)  Melting point; SDS-gel electrophoresis 
B)  SDS-gel electrophoresis; gel-filtration chromatography 
C)  Acrylamide gel electrophoresis; isoelectric focusing 
D)  Gel-filtration chromatography; SDS-gel electrophoresis 
E)  SDS-gel electrophoresis; NMR 
A)  Melting point; SDS-gel electrophoresis 
B)  SDS-gel electrophoresis; gel-filtration chromatography 
C)  Acrylamide gel electrophoresis; isoelectric focusing 
D)  Gel-filtration chromatography; SDS-gel electrophoresis 
E)  SDS-gel electrophoresis; NMR

Question 6

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

Question 7

For each term select the description that best describes its contribution to the structure of collagen. A) Has $ \mathrm{H} $ bonds which help stabilize the protein
B) Makes the protein rigid
C) Required for hydroxylation
D) Forms covalent cross links
E) Allows tightly wound helix formation
-Allysine

Accepted Answer

The answer of For each term select the description that...

Question 8

Disulfide bond formation between two cysteine residues appropriately located in a polypeptide chain drives protein folding into the proper configuration.

Accepted Answer

A) True 
 B)False

Question 9

Which pair represents different conformations?

Accepted Answer

A)  cis-1,2-dichloroethene and trans-1,2-dichloroethene 
B)  L-glycine and D-glycine 
C)  eclipsed ethane and staggered ethane 
D)  pentane and 2-methylbutane 
A)  cis-1,2-dichloroethene and trans-1,2-dichloroethene 
B)  L-glycine and D-glycine 
C)  eclipsed ethane and staggered ethane 
D)  pentane and 2-methylbutane

Question 10

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.

Question 11

Proteins often consist of multiple subunits so that they may have different functions under different conditions.

Accepted Answer

A) True 
 B)False

Question 12

Proteins with high Tm values are generally stable at

Accepted Answer

A)  room temperature 21 °
C) . 
B)  50 ° to 60 °C. 
C)  temperatures below 50 °C. 
D)  temperatures above 60 °C. 
E)  All of the above 
A)  room temperature 21 °
C) . 
B)  50 ° to 60 °C. 
C)  temperatures below 50 °C. 
D)  temperatures above 60 °C. 
E)  All of the above

Question 13

Structural proteins that typically assemble into large cables or threads to provide mechanical support to cells or organisms are classified as proteins.

Accepted Answer

A)  fibrous 
B)  enzyme 
C)  globular 
D)  β-strand 
A)  fibrous 
B)  enzyme 
C)  globular 
D)  β-strand

Question 14

At high carbon dioxide concentrations the carbamates of hemoglobin can be formed. The carbamates of oxyhemoglobin are less stable than those of deoxyhemoglobin.

Accepted Answer

A) True 
 B)False

Question 15

Proline is not often found in a-helices of proteins because it

Accepted Answer

A)  has a small, uncharged side chain. 
B)  has a very bulky side chain. 
C)  lacks a hydrogen atom on its amide nitrogen. 
D)  interacts with adjacent amino acids. 
A)  has a small, uncharged side chain. 
B)  has a very bulky side chain. 
C)  lacks a hydrogen atom on its amide nitrogen. 
D)  interacts with adjacent amino acids.

Question 16

Many proteins have multiple subunits because

Accepted Answer

A)  an active site is shared by different subunits. 
B)  they are more stable and flexible in movement. 
C)  different combinations can perform different functions. 
D)  All of the above 
E)  A and C above 
A)  an active site is shared by different subunits. 
B)  they are more stable and flexible in movement. 
C)  different combinations can perform different functions. 
D)  All of the above 
E)  A and C above

Question 17

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

Accepted Answer

A) True 
 B)False

Question 18

The distance along a helix axis for one complete turn is called the .

Accepted Answer

A)  axial distance 
B)  rise 
C)  screw length 
D)  pitch 
A)  axial distance 
B)  rise 
C)  screw length 
D)  pitch

Question 19

Which is evidence that structures for proteins determined by X-ray crystallography represent the structures in solution?

Accepted Answer

A)  Their similarity to structures determined by NMR. 
B)  The protein crystals are soluble in water. 
C)  The proteins must align in a regular pattern to form a crystal. 
D)  Only one conformation is ever possible for a protein so it is irrelevant whether the protein is in a crystal or in solution. 
A)  Their similarity to structures determined by NMR. 
B)  The protein crystals are soluble in water. 
C)  The proteins must align in a regular pattern to form a crystal. 
D)  Only one conformation is ever possible for a protein so it is irrelevant whether the protein is in a crystal or in solution.

Question 20

Using simple computer algorithms biochemists can easily predict the tertiary structure of a protein from its sequence.

Accepted Answer

A) True 
 B)False

Exam 4: Proteins: Three-Dimensional Structure and Function

The is the single shape a protein adopts under physiological conditions.

The porphyrin prosthetic group is held into the interior of globin molecules by covalent bonds to specific amino acid residues.

The subunits of a multisubunit proteins are always identical.

Chaotropic agents denature by disrupting stabilizing hydrophobic interactions, while detergents denature by penetrating and disrupting hydrophilic interactions.

is used to estimate the molecular weight of oligomeric proteins, while is used to determine molecular weight of each chain.

To what level of structure do α-helices belong?

Disulfide bond formation between two cysteine residues appropriately located in a polypeptide chain drives protein folding into the proper configuration.

Which pair represents different conformations?

Nearly all peptide bonds are in the trans configuration because

Proteins often consist of multiple subunits so that they may have different functions under different conditions.

Proteins with high Tm values are generally stable at

Structural proteins that typically assemble into large cables or threads to provide mechanical support to cells or organisms are classified as proteins.

At high carbon dioxide concentrations the carbamates of hemoglobin can be formed. The carbamates of oxyhemoglobin are less stable than those of deoxyhemoglobin.

Proline is not often found in a-helices of proteins because it

Many proteins have multiple subunits because

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

The distance along a helix axis for one complete turn is called the .

Which is evidence that structures for proteins determined by X-ray crystallography represent the structures in solution?

Using simple computer algorithms biochemists can easily predict the tertiary structure of a protein from its sequence.

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

Proteins with high T_mvalues are generally stable at