Question 1

Why is an assay necessary for protein purification studies?

Accepted Answer

An assay allows researchers to accurately measure the amount of the desired protein which allows the researcher to track the protein during the purification process. This is important in determining if particular purification steps are effective in isolating the protein from the other cellular material.

Question 2

Which of the following is often the first step in protein purification from a homogenate?

Accepted Answer

A)  ion exchange chromatography 
B)  gel-filtration chromatography 
C)  HPLC 
D)  centrifugation 
E)  gel electrophoresis 
A)  ion exchange chromatography 
B)  gel-filtration chromatography 
C)  HPLC 
D)  centrifugation 
E)  gel electrophoresis D

Question 3

In the Edman procedure for peptide sequence, phenyl isothiocyanate is used to selectively remove the __________________ residue as a PTH-derivative.

Accepted Answer

N-terminal

Question 4

The use of synthetic peptides includes

Accepted Answer

A)  use as antigens for making antibodies. 
B)  drugs. 
C)  "hooks" for use in affinity purification. 
D)  All of the answers are correct. 
E)  use as antigens for making antibodies and "hooks" for use in affinity purification. 
A)  use as antigens for making antibodies. 
B)  drugs. 
C)  "hooks" for use in affinity purification. 
D)  All of the answers are correct. 
E)  use as antigens for making antibodies and "hooks" for use in affinity purification.

Question 5

Which of the following affect the sedimentation rate of a particle?

Accepted Answer

A)  mass 
B)  shape 
C)  the density of the solution 
D)  All of the answers are correct. 
E)  mass and shape 
A)  mass 
B)  shape 
C)  the density of the solution 
D)  All of the answers are correct. 
E)  mass and shape

Question 6

Which technique cannot be used for quantitative analysis?

Accepted Answer

A)  x-ray crystallography 
B)  ELISA 
C)  absorbance spectroscopy 
D)  All of the answers are correct. 
E)  None of the answers is correct. 
A)  x-ray crystallography 
B)  ELISA 
C)  absorbance spectroscopy 
D)  All of the answers are correct. 
E)  None of the answers is correct.

Question 7

What is the advantage of adding SDS to gel electrophoresis?

Accepted Answer

A)  SDS colors the proteins for visualization. 
B)  SDS reduces disulfide bonds. 
C)  SDS allows proteins to be separated on the basis of approximate mass. 
D)  None of the answers is correct. 
E)  All of the answers are correct. 
A)  SDS colors the proteins for visualization. 
B)  SDS reduces disulfide bonds. 
C)  SDS allows proteins to be separated on the basis of approximate mass. 
D)  None of the answers is correct. 
E)  All of the answers are correct.

Question 8

When enzymes are purified, the assay is often based on

Accepted Answer

A)  light absorbance. 
B)  catalytic activity. 
C)  pH. 
D)  temperature changes. 
E)  mRNA levels. 
A)  light absorbance. 
B)  catalytic activity. 
C)  pH. 
D)  temperature changes. 
E)  mRNA levels.

Question 9

__________________ gels are often used as the media for electrophoretic techniques such as SDS-PAGE and isoelectric focusing.

Accepted Answer

The answer of __________________ gels are often used as the...

Question 10

Cyanogen bromide cleaves the peptide bond at

Accepted Answer

A)  the carboxyl side of Arg and Lys residues. 
B)  the carboxyl side of Met residues. 
C)  the amino terminus. 
D)  None of the answers is correct. 
E)  All of the answers are correct. 
A)  the carboxyl side of Arg and Lys residues. 
B)  the carboxyl side of Met residues. 
C)  the amino terminus. 
D)  None of the answers is correct. 
E)  All of the answers are correct.

Question 11

Molecular exclusion or gel-filtration chromatography separates molecules on the basis of __________________.

Accepted Answer

The answer of Molecular exclusion or gel-filtration chromatography separates molecules...

Question 12

Polypeptides can be fragmented into smaller peptides by cleavage with trypsin, which hydrolyzes the peptide bond at the C-terminal side of __________________ residues.

Accepted Answer

lysine and

Question 13

How are monoclonal antibodies made?

Accepted Answer

They are made by fusion of an

Question 14

What type of information can be obtained from ultracentrifugation?

Accepted Answer

This technique can be used to

Question 15

Describe the Edman degradation method for protein-sequence analysis.

Accepted Answer

A pure protein is reacted with phenyl is

Question 16

What is one advantage of using the recombinant DNA methods to determine protein sequences?

Accepted Answer

Large proteins can be difficul

Question 17

Which type of protein purification relies on the attraction of the protein for a particular chemical group?

Accepted Answer

A)  affinity chromatography 
B)  gel-filtration chromatography 
C)  HPLC 
D)  gel electrophoresis 
E)  isoelectric focusing 
A)  affinity chromatography 
B)  gel-filtration chromatography 
C)  HPLC 
D)  gel electrophoresis 
E)  isoelectric focusing

Question 18

What technique would be used to separate proteins with different sedimentation coefficients?

Accepted Answer

A)  MALDI-TOF mass spectrometry 
B)  zonal centrifugation 
C)  HPLC 
D)  gel-filtration chromatography 
E)  All of the answers are correct. 
A)  MALDI-TOF mass spectrometry 
B)  zonal centrifugation 
C)  HPLC 
D)  gel-filtration chromatography 
E)  All of the answers are correct.

Question 19

Long proteins are often treated with the enzyme ______________, which cleaves the protein into smaller, easily analyzed peptides.

Accepted Answer

trypsin OR

Question 20

Proteins can be separated from small molecules and ions through a semipermeable membrane by __________________.

Accepted Answer

The answer of Proteins can be separated from small molecules...

Exam 3: Exploring Proteins and Proteomes

Why is an assay necessary for protein purification studies?

Which of the following is often the first step in protein purification from a homogenate?

In the Edman procedure for peptide sequence, phenyl isothiocyanate is used to selectively remove the __________________ residue as a PTH-derivative.

The use of synthetic peptides includes

Which of the following affect the sedimentation rate of a particle?

Which technique cannot be used for quantitative analysis?

What is the advantage of adding SDS to gel electrophoresis?

When enzymes are purified, the assay is often based on

__________________ gels are often used as the media for electrophoretic techniques such as SDS-PAGE and isoelectric focusing.

Cyanogen bromide cleaves the peptide bond at

Molecular exclusion or gel-filtration chromatography separates molecules on the basis of __________________.

Polypeptides can be fragmented into smaller peptides by cleavage with trypsin, which hydrolyzes the peptide bond at the C-terminal side of __________________ residues.

How are monoclonal antibodies made?

What type of information can be obtained from ultracentrifugation?

Describe the Edman degradation method for protein-sequence analysis.

What is one advantage of using the recombinant DNA methods to determine protein sequences?

Which type of protein purification relies on the attraction of the protein for a particular chemical group?

What technique would be used to separate proteins with different sedimentation coefficients?

Long proteins are often treated with the enzyme ______________, which cleaves the protein into smaller, easily analyzed peptides.

Proteins can be separated from small molecules and ions through a semipermeable membrane by __________________.

Biochemistry: an Evolving Science

Protein Composition and Structure

DNA, RNA, and the Flow of Genetic Information

Exploring Genes and Genomes

Exploring Evolution and Bioinformatics

Hemoglobin: a Portrait of a Protein in Action

Enzymes: Basic Concepts and Kinetics

Oxidative Phosphorylation

Catalytic Strategies

Regulatory Strategies

Carbohydrates

Lipids and Cell Membranes

Membrane Channels and Pumps

Signal-Transduction Pathways

Metabolism: Basic Concepts and Design

Glycolysis and Gluconeogenesis

The Citric Acid Cycle

The Light Reactions of Photosynthesis

The Calvin Cycle and the Pentose Phosphate Pathway

Glycogen Metabolism

Fatty Acid Metabolism

Protein Turnover and Amino Acid Catabolism

The Biosynthesis of Amino Acids

Nucleotide Biosynthesis

Biosynthesis of Membrane Lipids and Steroids

The Integration of Metabolism

DNA Replication, Repair, and Recombination

Rna Synthesis and Processing

Protein Synthesis

The Control of Gene Expression in Prokaryotes

The Control of Gene Expression in Eukaryotes

Sensory Systems

The Immune System

Molecular Motors

Drug Development

Filters