Question 1

Which of the following amino acids would be last to elute at pH 8.0 from an anion-exchange column?

Accepted Answer

A) lysine 
B) alanine 
C) glutamic acid 
D) asparagine 
E) glycine 
A) lysine 
B) alanine 
C) glutamic acid 
D) asparagine 
E) glycine

Question 2

Natural proteins most commonly contain linear polypeptides between 100 and 1000 residues in length.One of the reasons polypeptides outside this range may be disfavored is that

Accepted Answer

A) larger polypeptides would likely be insoluble. 
B) smaller polypeptides do not form stable folded structures. 
C) smaller polypeptides typically assemble into prion-like aggregates. 
D) amide linkages are not strong enough to keep larger polypeptides intact. 
E) ribosomes are unable to synthesize larger polypeptides. 
A) larger polypeptides would likely be insoluble. 
B) smaller polypeptides do not form stable folded structures. 
C) smaller polypeptides typically assemble into prion-like aggregates. 
D) amide linkages are not strong enough to keep larger polypeptides intact. 
E) ribosomes are unable to synthesize larger polypeptides.

Question 3

SDS-PAGE separates proteins primarily due to differences in

Accepted Answer

A) isoelectric point. 
B) mass. 
C) polarity. 
D) solubility. 
E) amino acid sequence. 
A) isoelectric point. 
B) mass. 
C) polarity. 
D) solubility. 
E) amino acid sequence.

Question 4

Matching

-The endoprotease ______ cleaves polypeptides on the C-terminal side of certain bulky hydrophobic amino acid residues.

Accepted Answer

A)  electrophoresis 
B)  hydrophobic interaction 
C)  enzyme-linked immunosorbent assay 
D)  three-dimensional shape 
E)  N-terminal amino acid
F) negative charge
G) nucleases
H) chromophore
I) foaming 
J) high level expression
K) 2-mercaptoethanol
L) positive charge
M) cation exchange
N) pI
O) chymotrypsin
P) C-terminal amino acid
Q) Sodium dodecyl sulfate 
A)  electrophoresis 
B)  hydrophobic interaction 
C)  enzyme-linked immunosorbent assay 
D)  three-dimensional shape 
E)  N-terminal amino acid
F) negative charge
G) nucleases
H) chromophore
I) foaming 
J) high level expression
K) 2-mercaptoethanol
L) positive charge
M) cation exchange
N) pI
O) chymotrypsin
P) C-terminal amino acid
Q) Sodium dodecyl sulfate

Question 5

______________ has emerged as a technique for protein sequencing.

Accepted Answer

A) NMR spectroscopy 
B) Mass spectrometry 
C) Gel electrophoresis 
D) Phylogenetic analysis 
E) Limited proteolysis 
A) NMR spectroscopy 
B) Mass spectrometry 
C) Gel electrophoresis 
D) Phylogenetic analysis 
E) Limited proteolysis

Question 6

Matching

-In order for DEAE to act as an anion exchanger,it must have a ______.

Accepted Answer

A)  electrophoresis 
B)  hydrophobic interaction 
C)  enzyme-linked immunosorbent assay 
D)  three-dimensional shape 
E)  N-terminal amino acid
F) negative charge
G) nucleases
H) chromophore
I) foaming 
J) high level expression
K) 2-mercaptoethanol
L) positive charge
M) cation exchange
N) pI
O) chymotrypsin
P) C-terminal amino acid
Q) Sodium dodecyl sulfate 
A)  electrophoresis 
B)  hydrophobic interaction 
C)  enzyme-linked immunosorbent assay 
D)  three-dimensional shape 
E)  N-terminal amino acid
F) negative charge
G) nucleases
H) chromophore
I) foaming 
J) high level expression
K) 2-mercaptoethanol
L) positive charge
M) cation exchange
N) pI
O) chymotrypsin
P) C-terminal amino acid
Q) Sodium dodecyl sulfate

Question 7

Paralogous genes are

Accepted Answer

A) genes that do not encode protein. 
B) genes of slowly evolving proteins. 
C) relics of genes that are not expressed. 
D) genes of rapidly evolving proteins. 
E) the results of gene duplication. 
A) genes that do not encode protein. 
B) genes of slowly evolving proteins. 
C) relics of genes that are not expressed. 
D) genes of rapidly evolving proteins. 
E) the results of gene duplication.

Question 8

Matching

-Molecules that contain a(n)______ are capable of absorbing light.

Accepted Answer

A)  electrophoresis 
B)  hydrophobic interaction 
C)  enzyme-linked immunosorbent assay 
D)  three-dimensional shape 
E)  N-terminal amino acid
F) negative charge
G) nucleases
H) chromophore
I) foaming 
J) high level expression
K) 2-mercaptoethanol
L) positive charge
M) cation exchange
N) pI
O) chymotrypsin
P) C-terminal amino acid
Q) Sodium dodecyl sulfate 
A)  electrophoresis 
B)  hydrophobic interaction 
C)  enzyme-linked immunosorbent assay 
D)  three-dimensional shape 
E)  N-terminal amino acid
F) negative charge
G) nucleases
H) chromophore
I) foaming 
J) high level expression
K) 2-mercaptoethanol
L) positive charge
M) cation exchange
N) pI
O) chymotrypsin
P) C-terminal amino acid
Q) Sodium dodecyl sulfate

Question 9

You are interested in receptor protein-tyrosine kinases and you are purifying a novel phosphotyrosine-binding protein (NPBP-1).In order to characterize this protein you need to separate it from three other proteins (X,Y,and Z)that are still present in your partially purified material.The proteins in your preparation have the following properties:
   
a.What type of separation technique can be used to separate protein NPBP-1 from protein X?
b.What type of separation technique can be used to separate protein NPBP-1 from protein Y?
c.What type of separation technique can be used to separate protein NPBP-1 from protein Z?

Accepted Answer

a.On a size (mass)basis:gel permeation c

Question 10

Which physical characteristic is not commonly used in protein separation?

Accepted Answer

A) solubility 
B) stereochemistry 
C) size 
D) charge 
E) polarity 
A) solubility 
B) stereochemistry 
C) size 
D) charge 
E) polarity

Question 11

Which of these are commonly used to cleave peptide bonds in polypeptides?

Accepted Answer

A) 2-mercaptoethanol ($\beta$-M
E)  
B) dansyl chloride 
C) iodoacetate 
D) sodium dodecyl sulfate 
E) trypsin 
A) 2-mercaptoethanol ($\beta$-M
E)  
B) dansyl chloride 
C) iodoacetate 
D) sodium dodecyl sulfate 
E) trypsin

Question 12

The pK1,pK2,and pKR of the amino acid histdine are 1.8,9.3,and 6.0,respectively.The pK1,pK2,and pKR of the amino acid arginine are 1.8,9.0,and 12.5,respectively.You have a mixture of histidine and arginine,how would you try to separate these two amino acids?

Accepted Answer

A) anion exchange chromatography at pH 2 
B) anion exchange chromatography at pH 4 
C) cation exchange chromatography at pH 2 
D) cation exchange chromatography at pH 4 
E) cation exchange chromatography at pH 9 
A) anion exchange chromatography at pH 2 
B) anion exchange chromatography at pH 4 
C) cation exchange chromatography at pH 2 
D) cation exchange chromatography at pH 4 
E) cation exchange chromatography at pH 9

Question 13

Matching

-If antibodies to the protein being assayed are available,a(n)______ can be carried out.

Accepted Answer

A)  electrophoresis 
B)  hydrophobic interaction 
C)  enzyme-linked immunosorbent assay 
D)  three-dimensional shape 
E)  N-terminal amino acid
F) negative charge
G) nucleases
H) chromophore
I) foaming 
J) high level expression
K) 2-mercaptoethanol
L) positive charge
M) cation exchange
N) pI
O) chymotrypsin
P) C-terminal amino acid
Q) Sodium dodecyl sulfate 
A)  electrophoresis 
B)  hydrophobic interaction 
C)  enzyme-linked immunosorbent assay 
D)  three-dimensional shape 
E)  N-terminal amino acid
F) negative charge
G) nucleases
H) chromophore
I) foaming 
J) high level expression
K) 2-mercaptoethanol
L) positive charge
M) cation exchange
N) pI
O) chymotrypsin
P) C-terminal amino acid
Q) Sodium dodecyl sulfate

Question 14

Which of these reagents is commonly used to determine the number of polypeptides in a protein?

Accepted Answer

A) iodoacetate 
B) dansyl chloride 
C) 2-mercaptoethanol ($\beta$-M
E)  
D) cyanogen bromide 
E) DEAE 
A) iodoacetate 
B) dansyl chloride 
C) 2-mercaptoethanol ($\beta$-M
E)  
D) cyanogen bromide 
E) DEAE

Question 15

A first step in purifying a protein that was initially associated with fatty substances would be

Accepted Answer

A) Coomassie Brilliant Blue dye staining. 
B) analytical ultracentrifugation. 
C) ELISA. 
D) Western blotting. 
E) hydrophobic interaction chromatography. 
A) Coomassie Brilliant Blue dye staining. 
B) analytical ultracentrifugation. 
C) ELISA. 
D) Western blotting. 
E) hydrophobic interaction chromatography.

Question 16

What can be done to increase the rate at which a protein of interest moves down an ion-exchange chromatography column?

Accepted Answer

A) reduce the ion concentration in the eluant 
B) add a small amount of a non-ionic detergents to the eluant 
C) change the pH of the eluant 
D) add a protease inhibitor to the eluant 
E) reduce the temperature of the eluant 
A) reduce the ion concentration in the eluant 
B) add a small amount of a non-ionic detergents to the eluant 
C) change the pH of the eluant 
D) add a protease inhibitor to the eluant 
E) reduce the temperature of the eluant

Question 17

Matching

-If the cDNA for a protein has been cloned,it may be possible to obtain large quantities of the protein by _________________ in bacteria.

Accepted Answer

A)  electrophoresis 
B)  hydrophobic interaction 
C)  enzyme-linked immunosorbent assay 
D)  three-dimensional shape 
E)  N-terminal amino acid
F) negative charge
G) nucleases
H) chromophore
I) foaming 
J) high level expression
K) 2-mercaptoethanol
L) positive charge
M) cation exchange
N) pI
O) chymotrypsin
P) C-terminal amino acid
Q) Sodium dodecyl sulfate 
A)  electrophoresis 
B)  hydrophobic interaction 
C)  enzyme-linked immunosorbent assay 
D)  three-dimensional shape 
E)  N-terminal amino acid
F) negative charge
G) nucleases
H) chromophore
I) foaming 
J) high level expression
K) 2-mercaptoethanol
L) positive charge
M) cation exchange
N) pI
O) chymotrypsin
P) C-terminal amino acid
Q) Sodium dodecyl sulfate

Question 18

Hydrophobic interaction chromatography can be used to separate proteins based on differences in

Accepted Answer

A) ionic charge. 
B) solubility. 
C) size. 
D) polarity. 
E) binding specificity. 
A) ionic charge. 
B) solubility. 
C) size. 
D) polarity. 
E) binding specificity.

Question 19

The quantitation of proteins due to their absorbance at ~280 nm (UV region)is due to the large absorbtivity of the ________ amino acids.

Accepted Answer

A) anionic 
B) dansylated 
C) cleaved 
D) polar 
E) aromatic 
A) anionic 
B) dansylated 
C) cleaved 
D) polar 
E) aromatic

Question 20

The acronym HPLC stands for

Accepted Answer

A) hydrophobic protein liquid chromatography. 
B) high performance liquid chromatography. 
C) hydrophilic partition liquid chromatography. 
D) high priced liquid chromatography. 
E) hydrostatic process liquid chromatography. 
A) hydrophobic protein liquid chromatography. 
B) high performance liquid chromatography. 
C) hydrophilic partition liquid chromatography. 
D) high priced liquid chromatography. 
E) hydrostatic process liquid chromatography.

Exam 5: Proteins: Primary Structure

Which of the following amino acids would be last to elute at pH 8.0 from an anion-exchange column?

Natural proteins most commonly contain linear polypeptides between 100 and 1000 residues in length.One of the reasons polypeptides outside this range may be disfavored is that

SDS-PAGE separates proteins primarily due to differences in

Matching -The endoprotease ______ cleaves polypeptides on the C-terminal side of certain bulky hydrophobic amino acid residues.

______________ has emerged as a technique for protein sequencing.

Matching -In order for DEAE to act as an anion exchanger,it must have a ______.

Paralogous genes are

Matching -Molecules that contain a(n)______ are capable of absorbing light.

Which physical characteristic is not commonly used in protein separation?

Which of these are commonly used to cleave peptide bonds in polypeptides?

The pK1,pK2,and pKR of the amino acid histdine are 1.8,9.3,and 6.0,respectively.The pK1,pK2,and pKR of the amino acid arginine are 1.8,9.0,and 12.5,respectively.You have a mixture of histidine and arginine,how would you try to separate these two amino acids?

Matching -If antibodies to the protein being assayed are available,a(n)______ can be carried out.

Which of these reagents is commonly used to determine the number of polypeptides in a protein?

A first step in purifying a protein that was initially associated with fatty substances would be

What can be done to increase the rate at which a protein of interest moves down an ion-exchange chromatography column?

Matching -If the cDNA for a protein has been cloned,it may be possible to obtain large quantities of the protein by _________________ in bacteria.

Hydrophobic interaction chromatography can be used to separate proteins based on differences in

The quantitation of proteins due to their absorbance at ~280 nm (UV region)is due to the large absorbtivity of the ________ amino acids.

The acronym HPLC stands for

Introduction to the Chemistry of Life

Water

Nucleotides, nucleic Acids, and Genetic Information

Amino Acids

Proteins: Three-Dimensional 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

The pK₁,pK₂,and pK_R of the amino acid histdine are 1.8,9.3,and 6.0,respectively.The pK₁,pK₂,and pK_R of the amino acid arginine are 1.8,9.0,and 12.5,respectively.You have a mixture of histidine and arginine,how would you try to separate these two amino acids?