Deck 5: Techniques in Protein Biochemistry

Question 1

In amino acid composition analysis, amino acids are visualized after separation using the chemical reagent _______________.

Answer 1

fluorescamine

Question 2

In the Edman procedure for peptide sequence, phenyl isothiocyanate is used to selectively derivitize the __________________ residue, which is then removed as a PTH derivative.

Answer 2

N-terminal

Question 3

Use the following to answer questions 1-10:
Choose the correct answer from the list below. Not all of the answers will be used.
a) HPLC
b) specific activity
c) MALDI-TOF mass spectrum
d) gradient centrifugation
e) proteome
f) SDS
g) two-dimensional electrophoresis
h) Svedberg
i) immunoglobulin
j) differential centrifugation
k) overlap peptides
l) affinity chromatography
The subset of gene products actually expressed by the cell is ____________.

Answer 3

e

Question 4

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

Question 5

Use the following to answer questions 1-10:
Choose the correct answer from the list below. Not all of the answers will be used.
a) HPLC
b) specific activity
c) MALDI-TOF mass spectrum
d) gradient centrifugation
e) proteome
f) SDS
g) two-dimensional electrophoresis
h) Svedberg
i) immunoglobulin
j) differential centrifugation
k) overlap peptides
l) affinity chromatography
____________: The separation of proteins based first on charge then size.

Question 6

Use the following to answer questions 1-10:
Choose the correct answer from the list below. Not all of the answers will be used.
a) HPLC
b) specific activity
c) MALDI-TOF mass spectrum
d) gradient centrifugation
e) proteome
f) SDS
g) two-dimensional electrophoresis
h) Svedberg
i) immunoglobulin
j) differential centrifugation
k) overlap peptides
l) affinity chromatography
In order to sequence a whole protein, ____________ are used.

Question 7

Using antibodies as reagents to quantify proteins or other antigens is the basis for the technique called ________________.

Question 8

Use the following to answer questions 1-10:
Choose the correct answer from the list below. Not all of the answers will be used.
a) HPLC
b) specific activity
c) MALDI-TOF mass spectrum
d) gradient centrifugation
e) proteome
f) SDS
g) two-dimensional electrophoresis
h) Svedberg
i) immunoglobulin
j) differential centrifugation
k) overlap peptides
l) affinity chromatography
The ratio of enzyme activity relative to total protein is called ____________.

Question 9

When enzymes are purified, the assay is often based on:

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

Question 10

The ________________ of a protein is the pH at which its net charge is zero.

Question 11

Use the following to answer questions 1-10:
Choose the correct answer from the list below. Not all of the answers will be used.
a) HPLC
b) specific activity
c) MALDI-TOF mass spectrum
d) gradient centrifugation
e) proteome
f) SDS
g) two-dimensional electrophoresis
h) Svedberg
i) immunoglobulin
j) differential centrifugation
k) overlap peptides
l) affinity chromatography
Sedimentation coefficients are expressed in ____________ units.

Question 12

Use the following to answer questions 1-10:
Choose the correct answer from the list below. Not all of the answers will be used.
a) HPLC
b) specific activity
c) MALDI-TOF mass spectrum
d) gradient centrifugation
e) proteome
f) SDS
g) two-dimensional electrophoresis
h) Svedberg
i) immunoglobulin
j) differential centrifugation
k) overlap peptides
l) affinity chromatography
Proteins with different sedimentation coefficients can be separated by ____________.

Question 13

________________ allows the detection of small amounts of target proteins as well as the ability to determine the size of target proteins.

Question 14

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

Question 15

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

Question 16

Use the following to answer questions 1-10:
Choose the correct answer from the list below. Not all of the answers will be used.
a) HPLC
b) specific activity
c) MALDI-TOF mass spectrum
d) gradient centrifugation
e) proteome
f) SDS
g) two-dimensional electrophoresis
h) Svedberg
i) immunoglobulin
j) differential centrifugation
k) overlap peptides
l) affinity chromatography
____________ can be added prior to gel electrophoresis to denature the proteins.

Question 17

Use the following to answer questions 1-10:
Choose the correct answer from the list below. Not all of the answers will be used.
a) HPLC
b) specific activity
c) MALDI-TOF mass spectrum
d) gradient centrifugation
e) proteome
f) SDS
g) two-dimensional electrophoresis
h) Svedberg
i) immunoglobulin
j) differential centrifugation
k) overlap peptides
l) affinity chromatography
The first step in protein purification from a homogenate is usually ____________.

Question 18

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

Question 19

Use the following to answer questions 1-10:
Choose the correct answer from the list below. Not all of the answers will be used.
a) HPLC
b) specific activity
c) MALDI-TOF mass spectrum
d) gradient centrifugation
e) proteome
f) SDS
g) two-dimensional electrophoresis
h) Svedberg
i) immunoglobulin
j) differential centrifugation
k) overlap peptides
l) affinity chromatography
____________: A type of purification that is based on the attraction of the protein for a particular chemical group.

Question 20

Use the following to answer questions 1-10:
Choose the correct answer from the list below. Not all of the answers will be used.
a) HPLC
b) specific activity
c) MALDI-TOF mass spectrum
d) gradient centrifugation
e) proteome
f) SDS
g) two-dimensional electrophoresis
h) Svedberg
i) immunoglobulin
j) differential centrifugation
k) overlap peptides
l) affinity chromatography
____________: A protein purification technique characterized by high resolution and rapid separation.

Question 21

What is the advantage of adding SDS to gel electrophoresis?

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 above.
E) All of the above.

Question 22

Which of the following techniques can be used to determine the size of a target protein?

A) Edman degradation
B) Affinity chromatography
C) SDS polyacrylamide gel electrophoresis
D) ELISA
E) Isoelectric-focusing gel

Question 23

Which technique cannot be used for quantitative analysis?

A) zonal centrifugation
B) ELISA
C) enzyme assay
D) All of the above.
E) None of the above.

Question 24

Proteins that are not catalysts are often assayed using:

A) antibody-binding assays.
B) enzymatic activity.
C) amino acid analysis.
D) None of the above.
E) All of the above.

Question 25

Which conditions could cause changes in the proteome of a cell?

A) the developmental stage
B) the environmental condition
C) enzymatic modification
D) All of the above.
E) None of the above

Question 26

How do gel-filtration and ion-exchange chromatography differ?

Question 27

How can a protein's isoelectric point be used in protein purification?

Question 28

Which types of molecules can serve as antigens?

A) proteins
B) polysaccharides
C) metal ions
D) All of the above.
E) A and B

Question 29

Which of the following affects the sedimentation of a particle?

A) mass
B) shape
C) the density of the solution
D) All of the above.
E) A and B

Question 30

Why is an assay necessary for protein-purification studies?

Question 31

Cyanogen bromide cleaves the peptide bond at:

A) the carboxyl side of Arginine and Lysine residues.
B) the carboxyl side of Methionine residues.
C) the amino terminus.
D) None of the above.
E) All of the above.

Question 32

Trypsin cleaves the peptide bond at:

A) the carboxyl side of Arginine and Lysine residues.
B) the carboxyl side of Methionine residues.
C) the amino terminus.
D) None of the above.
E) All of the above.

Question 33

Describe the Edman degradation method for protein-sequence analysis.

Question 34

Which of the following is true regarding gel-filtration chromatography and PAGE?

A) In both, small proteins move most rapidly.
B) In both, large proteins move most rapidly.
C) In PAGE, large proteins move most rapidly but in gel filtration, small proteins move most rapidly.
D) In gel filtration, large proteins move most rapidly, but in PAGE, small proteins move most rapidly.
E) None of the above.

Question 35

How can the amino acid sequences be used to design a DNA probe?

Question 36

What type of information can be obtained from gradient centrifugation?

Question 37

What is the purpose of determining the specific activity, yield, and purification level of a protein-purification protocol?

Question 38

Two-dimensional electrophoresis is a combination of which two techniques?

A) isoelectric focusing and affinity chromatography
B) ion-exchange chromatography and SDS-PAGE
C) affinity chromatography and SDS-PAGE
D) isoelectric focusing and SDS-PAGE
E) isoelectric focusing and ion-exchange chromatography

Question 39

How is lactic acid dehydrogenase assayed?

Question 40

Affinity chromatography:

A) allows high resolution and rapid separation.
B) separates proteins based on size.
C) separates proteins based on charge.
D) separates proteins based on attraction to another molecule.
E) separates proteins based on charge and size.

Question 41

Explain the trend of specific activity as a protein is purified.

Question 42

Start with a technique used on a complex mixture of proteins, such as a cell lysate, through a series of steps to a pure protein.

Question 43

Why is there a need for different digestion tools when fingerprinting a protein?

Question 44

Explain the process of immunoprecipitation.