Question 1

Which substance would you expect to be eluted first from a molecular sieve column with a suitable degree of crosslinking?

Accepted Answer

A)  hemoglobin 
B)  myoglobin 
C)  2,3-bisphosphoglycerate 
D)  all would elute at the same rate 
A)  hemoglobin 
B)  myoglobin 
C)  2,3-bisphosphoglycerate 
D)  all would elute at the same rate A

Question 2

Which of the following treatments results in a polypeptide fragment with a homoserine lactone at the C-terminal end?

Accepted Answer

A)  trypsin 
B)  chymotrypsin 
C)  cyanogen bromide 
D)  Edman method 
A)  trypsin 
B)  chymotrypsin 
C)  cyanogen bromide 
D)  Edman method C

Question 3

A chromatography technique where a solution of nonpolar compounds is put through a column that has a nonpolar liquid immobilized on an inert matrix is which type of chromatography?

Accepted Answer

A)  Gel filtration 
B)  Ion exchange 
C)  Affinity 
D)  HPLC 
E)  Reverse Phase HPLC 
A)  Gel filtration 
B)  Ion exchange 
C)  Affinity 
D)  HPLC 
E)  Reverse Phase HPLC E

Question 4

The typical order of differential centrifugation for organelles is (from slowest speed/lowest g to fastest speed/highest g):

Accepted Answer

A)  nuclei, microsomes, mitochondria & chloroplasts, cytosol, whole cells 
B)  whole cells, nuclei, mitochondria & chloroplasts, microsomes, cytosol 
C)  cytosol, microsomes, nuclei, mitochondria & chloroplasts, whole cells 
D)  nuclei, mitochondria & chloroplasts, whole cells, cytosol, microsomes 
E)  whole cells, cytosol, microsomes, nuclei, mitochondria & chloroplasts 
A)  nuclei, microsomes, mitochondria & chloroplasts, cytosol, whole cells 
B)  whole cells, nuclei, mitochondria & chloroplasts, microsomes, cytosol 
C)  cytosol, microsomes, nuclei, mitochondria & chloroplasts, whole cells 
D)  nuclei, mitochondria & chloroplasts, whole cells, cytosol, microsomes 
E)  whole cells, cytosol, microsomes, nuclei, mitochondria & chloroplasts

Question 5

In electrophoresis experiments

Accepted Answer

A)  the separation must be carried out in bright light 
B)  the polarity of substances to be separated is more important than their charge or size 
C)  the sample can be badly degraded as a result of the separation 
D)  an electric field must be applied to the mixture to be separated 
A)  the separation must be carried out in bright light 
B)  the polarity of substances to be separated is more important than their charge or size 
C)  the sample can be badly degraded as a result of the separation 
D)  an electric field must be applied to the mixture to be separated

Question 6

Which of the following happens as a protein is purified?

Accepted Answer

A)  the percent recovery and the fold purification both increase 
B)  the percent recovery and the fold purification both decrease 
C)  the percent recovery increases and the fold purification decreases 
D)  the percent recovery decreases and the fold purification increases 
A)  the percent recovery and the fold purification both increase 
B)  the percent recovery and the fold purification both decrease 
C)  the percent recovery increases and the fold purification decreases 
D)  the percent recovery decreases and the fold purification increases

Question 7

Two-dimensional electrophoresis usually exploits these 2 different properties of proteins:

Accepted Answer

A)  Molecular weight and shape 
B)  Molecular weight and net charge 
C)  Molecular weight and isoionic pH 
D)  Isoionic pH and shape 
E)  Isoionic pH and net charge 
A)  Molecular weight and shape 
B)  Molecular weight and net charge 
C)  Molecular weight and isoionic pH 
D)  Isoionic pH and shape 
E)  Isoionic pH and net charge

Question 8

It is impossible to sequence a protein if you do not have overlapping sequences to work with.

Accepted Answer

A) True 
 B)False

Question 9

Matrix-Assisted Laser Desorption Ionization is a type of _____ technique.

Accepted Answer

A)  electrophoresis 
B)  ion exchange chromatography 
C)  affinity chromatography 
D)  mass spectrometry 
A)  electrophoresis 
B)  ion exchange chromatography 
C)  affinity chromatography 
D)  mass spectrometry

Question 10

If a protein with the sequence FEWPRQVDMARINE is treated with chymotrypsin, what will the products be?

Accepted Answer

A)  F EW PRQVMARINE 
B)  FE WPRQVD MARINE 
C)  FEWPR QVDMAR INE 
D)  FEWPRQVDM ARINE 
A)  F EW PRQVMARINE 
B)  FE WPRQVD MARINE 
C)  FEWPR QVDMAR INE 
D)  FEWPRQVDM ARINE

Question 11

Generally speaking, sequence techniques have become so sensitive that if you are able to isolate the protein on a gel, there is enough of it to get a significant amount of its sequence.

Accepted Answer

A) True 
 B)False

Question 12

How many bands would be produced when hemoglobin is subjected to SDS-PAGE?

Accepted Answer

A)  1 
B)  2 
C)  3 
D)  4 
E)  2, but only if the size of the pores in the gel would allow two proteins of slightly different size to be separated 
A)  1 
B)  2 
C)  3 
D)  4 
E)  2, but only if the size of the pores in the gel would allow two proteins of slightly different size to be separated

Question 13

When end-group analysis was done on the protein insulin, the results indicated that both glycine and phenylalanine were N-terminal amino acids and both asparagine and alanine were C-terminal amino acids. These results indicate that

Accepted Answer

A)  the experiment was done incorrectly 
B)  no conclusions can be drawn 
C)  there were impurities in the sample 
D)  insulin consists of two polypeptide chains 
A)  the experiment was done incorrectly 
B)  no conclusions can be drawn 
C)  there were impurities in the sample 
D)  insulin consists of two polypeptide chains

Question 14

Studying how proteins interact with other proteins is called

Accepted Answer

A)  expression proteomics 
B)  structural proteomics 
C)  interaction proteomics 
D)  none of the choices 
A)  expression proteomics 
B)  structural proteomics 
C)  interaction proteomics 
D)  none of the choices

Question 15

Important steps in sequencing pure proteins include all of these except:

Accepted Answer

A)  Determining the amino acid composition 
B)  Determining the isoionic pH of the protein 
C)  Breaking the protein into smaller peptides 
D)  Determining the amino acids on the ends of the protein 
E)  Determining the amino acids on the ends of the smaller peptides 
A)  Determining the amino acid composition 
B)  Determining the isoionic pH of the protein 
C)  Breaking the protein into smaller peptides 
D)  Determining the amino acids on the ends of the protein 
E)  Determining the amino acids on the ends of the smaller peptides

Question 16

Which of the following is NOT true concerning a western blot?

Accepted Answer

A)  it is usually performed in a 96 well microtiter plate 
B)  it involves the use of primary antibodies 
C)  it involves the use of secondary antibodies 
D)  it involves electrophoresis 
A)  it is usually performed in a 96 well microtiter plate 
B)  it involves the use of primary antibodies 
C)  it involves the use of secondary antibodies 
D)  it involves electrophoresis

Question 17

It is frequently possible to bypass the determination of the identity of the N-terminal amino acid of a protein because

Accepted Answer

A)  this information is already available from the amino acid analysis 
B)  the Edman method sequences the peptide from the N-terminal end 
C)  N-terminal amino acids are always chemically modified 
D)  this information is not needed 
A)  this information is already available from the amino acid analysis 
B)  the Edman method sequences the peptide from the N-terminal end 
C)  N-terminal amino acids are always chemically modified 
D)  this information is not needed

Question 18

In chromatography the experimental setup always requires

Accepted Answer

A)  a stationary phase and a mobile phase 
B)  a spectrophotometric detecting device 
C)  a sample in which components differ in charge 
D)  a sample in which components differ in polarity 
A)  a stationary phase and a mobile phase 
B)  a spectrophotometric detecting device 
C)  a sample in which components differ in charge 
D)  a sample in which components differ in polarity

Question 19

Elution of proteins by means of a pH gradient would work best with this type of column:

Accepted Answer

A)  Gel filtration 
B)  Affinity chromatography 
C)  Cation exchange 
D)  Anion exchange 
E)  Cation or anion exchange 
A)  Gel filtration 
B)  Affinity chromatography 
C)  Cation exchange 
D)  Anion exchange 
E)  Cation or anion exchange

Question 20

Differential centrifugation at low speeds (several thousand RPM) is a useful step when

Accepted Answer

A)  organelles have been lysed. 
B)  enzymes of interest have different sizes. 
C)  cell membranes must be left intact. 
D)  ribosomes need to be broken down. 
E)  there are either organelles or debris to separate. 
A)  organelles have been lysed. 
B)  enzymes of interest have different sizes. 
C)  cell membranes must be left intact. 
D)  ribosomes need to be broken down. 
E)  there are either organelles or debris to separate.

Exam 5: Protein Purification and Characterization Techniques

Which substance would you expect to be eluted first from a molecular sieve column with a suitable degree of crosslinking?

Which of the following treatments results in a polypeptide fragment with a homoserine lactone at the C-terminal end?

A chromatography technique where a solution of nonpolar compounds is put through a column that has a nonpolar liquid immobilized on an inert matrix is which type of chromatography?

The typical order of differential centrifugation for organelles is (from slowest speed/lowest g to fastest speed/highest g):

In electrophoresis experiments

Which of the following happens as a protein is purified?

Two-dimensional electrophoresis usually exploits these 2 different properties of proteins:

It is impossible to sequence a protein if you do not have overlapping sequences to work with.

Matrix-Assisted Laser Desorption Ionization is a type of _____ technique.

If a protein with the sequence FEWPRQVDMARINE is treated with chymotrypsin, what will the products be?

Generally speaking, sequence techniques have become so sensitive that if you are able to isolate the protein on a gel, there is enough of it to get a significant amount of its sequence.

How many bands would be produced when hemoglobin is subjected to SDS-PAGE?

When end-group analysis was done on the protein insulin, the results indicated that both glycine and phenylalanine were N-terminal amino acids and both asparagine and alanine were C-terminal amino acids. These results indicate that

Studying how proteins interact with other proteins is called

Important steps in sequencing pure proteins include all of these except:

Which of the following is NOT true concerning a western blot?

It is frequently possible to bypass the determination of the identity of the N-terminal amino acid of a protein because

In chromatography the experimental setup always requires

Elution of proteins by means of a pH gradient would work best with this type of column:

Differential centrifugation at low speeds (several thousand RPM) is a useful step when

Biochemistry and the Organization of Cells

Water: the Solvent for Biochemical Reactions

Amino Acids and Peptides

The Three-Dimensional Structure of Proteins

The Behavior of Proteins: Enzymes

The Behavior of Proteins: Enzymes, Mechanisms, and Control

Lipids and Proteins Are Associated in Biological Membranes

Nucleic Acids: How Structure Conveys Information

Biosynthesis of Nucleic Acids: Replication

Transcription of the Genetic Code: Biosynthesis of RNA

Protein Synthesis: Translation of the Genetic Message

Nucleic Acid Biotechnology Techniques

Viruses, Cancer, and Immunology

The Importance of Energy Changes and Electron Transfer in Metabolism

Carbohydrates

Glycolysis

Storage Mechanisms and Control in Carbohydrate Metabolism

The Citric Acid Cycle

Electron Transport and Oxidative Phosphorylation

Lipid Metabolism

Photosynthesis

The Metabolism of Nitrogen

Integration of Metabolism: Cellular Signaling

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