Question 1

Human tears contain approximately 500 different proteins.

Accepted Answer

A) True 
 B)False  True

Question 2

How would the results be impacted if a collision cell was not functioning?

Accepted Answer

The collision cell is a second stage of fragmentation that occurs after the initial separation of proteins in a mass spectrometer.Since precision of m/z measurement is higher for smaller molecules,this second stage fractionation makes more precise measurements than could be made with the intact peptide.All of these data are put together in a mass spectrum.Without the collision cell (assuming the ions were still able to be analyzed),a spectrum with peaks in the right place would still be produced,but the resolution of the peaks would be reduced.

Question 3

Which of the following is not a component of a mass spectrometry system used to identify proteins?

Accepted Answer

A)  ionization 
B)  mass analyzer 
C)  detector 
D)  computer 
E)  gas chromatograph 
A)  ionization 
B)  mass analyzer 
C)  detector 
D)  computer 
E)  gas chromatograph E

Question 4

Compare all of the methods of identifying protein interactions in terms of their relative advantages and disadvantages.

Accepted Answer

Yeast two-hybrid (Y2H)does not require a

Question 5

You are conducting a yeast two-hybrid experiment to discover proteins that interact with a particular protein of interest (protein X).Which of the following would be a useful step in this process?

Accepted Answer

A)  Fuse X to the HIS3 promoter. 
B)  Fuse X to a DNA binding domain. 
C)  Fuse X to the complete HIS3 gene. 
D)  Purify X from recombinant yeast. 
E)  Fuse X to the complete Gal4 gene. 
A)  Fuse X to the HIS3 promoter. 
B)  Fuse X to a DNA binding domain. 
C)  Fuse X to the complete HIS3 gene. 
D)  Purify X from recombinant yeast. 
E)  Fuse X to the complete Gal4 gene.

Question 6

Which of the following is not an example of posttranslational modification?

Accepted Answer

A)  phosphorylation 
B)  polyadenylation 
C)  glycosylation 
D)  ubiquitination 
E)  acetylation 
A)  phosphorylation 
B)  polyadenylation 
C)  glycosylation 
D)  ubiquitination 
E)  acetylation

Question 7

Approximately how many protein coding genes are encoded in the human genome?

Accepted Answer

A)  500 
B)  5,000 
C)  25,000 
D)  50,000 
E)  500,000 
A)  500 
B)  5,000 
C)  25,000 
D)  50,000 
E)  500,000

Question 8

The Gal4 DNA binding domain will bind to any eukaryotic promoter.

Accepted Answer

A) True 
 B)False

Question 9

In a typical yeast two-hybrid experiment,which of the following occurs when bait and prey interact?

Accepted Answer

A)  HIS3 binds to the promoter of a reporter gene. 
B)  Gal4 activator and binding domains form a complex. 
C)  HIS3 and Gal4 form a complex. 
D)  HIS3 transcription is blocked. 
E)  Expression of Gal4 is activated. 
A)  HIS3 binds to the promoter of a reporter gene. 
B)  Gal4 activator and binding domains form a complex. 
C)  HIS3 and Gal4 form a complex. 
D)  HIS3 transcription is blocked. 
E)  Expression of Gal4 is activated.

Question 10

In ICAT labelling,heavy and light linkers differ by 8kDa.

Accepted Answer

A) True 
 B)False

Question 11

Which of these moves most quickly through a mass spectrometer?

Accepted Answer

A)  a large,uncharged molecule 
B)  a small,uncharged molecule 
C)  a large,charged molecule 
D)  a small,charged molecule 
E)  an uncharged protein complex 
A)  a large,uncharged molecule 
B)  a small,uncharged molecule 
C)  a large,charged molecule 
D)  a small,charged molecule 
E)  an uncharged protein complex

Question 12

In ICAT (isotope coded affinity tag)methods,proteins are labelled with radioactive isotopes.

Accepted Answer

A) True 
 B)False

Question 13

Which of the following is not directly involved in ICAT (isotope coded affinity tag)labelling and purification?

Accepted Answer

A)  cysteine 
B)  deuterium 
C)  avidin 
D)  biotin 
E)  antibodies 
A)  cysteine 
B)  deuterium 
C)  avidin 
D)  biotin 
E)  antibodies

Question 14

What is the role of Gal4 in yeast two-hybrid experiments?

Accepted Answer

A)  It is a selectable marker. 
B)  It is a reporter gene. 
C)  It metabolizes galactose,which is used as an energy source. 
D)  It is split into two domains that together promote transcription of a target gene. 
E)  Its ability to interact with other proteins is tested. 
A)  It is a selectable marker. 
B)  It is a reporter gene. 
C)  It metabolizes galactose,which is used as an energy source. 
D)  It is split into two domains that together promote transcription of a target gene. 
E)  Its ability to interact with other proteins is tested.

Question 15

Each cell can be considered to have its own proteome.

Accepted Answer

A) True 
 B)False

Question 16

Which of the following would be required for affinity purification but not for yeast two-hybrid (Y2H)?

Accepted Answer

A)  A fusion protein including the protein of interest. 
B)  A fluorescent reporter gene. 
C)  A selectable marker. 
D)  An antibody. 
E)  An antibiotic. 
A)  A fusion protein including the protein of interest. 
B)  A fluorescent reporter gene. 
C)  A selectable marker. 
D)  An antibody. 
E)  An antibiotic.

Question 17

What accounts for the differences between the number of protein coding genes in the genome and the number of different proteins expressed?

Accepted Answer

A)  Not all genes are translated,so the number of expressed proteins is lower than the number of protein coding genes. 
B)  Not all genes are transcribed,so the number of expressed proteins is lower than the number of protein coding genes. 
C)  Alternative splicing is very common and increases the diversity of expressed proteins so the number of expressed proteins is higher than the number of protein coding genes. 
D)  Alternative splicing is very common and decreases the diversity of expressed proteins so the number of expressed proteins is lower than the number of protein coding genes. 
E)  Protein turnover is rapid and decreases the diversity of expressed proteins so the number of expressed proteins is lower than the number of protein coding genes. 
A)  Not all genes are translated,so the number of expressed proteins is lower than the number of protein coding genes. 
B)  Not all genes are transcribed,so the number of expressed proteins is lower than the number of protein coding genes. 
C)  Alternative splicing is very common and increases the diversity of expressed proteins so the number of expressed proteins is higher than the number of protein coding genes. 
D)  Alternative splicing is very common and decreases the diversity of expressed proteins so the number of expressed proteins is lower than the number of protein coding genes. 
E)  Protein turnover is rapid and decreases the diversity of expressed proteins so the number of expressed proteins is lower than the number of protein coding genes.

Question 18

Which of the following tasks is most often performed by robots during yeast two-hybrid screens?

Accepted Answer

A)  prey cloning 
B)  bait cloning 
C)  replica pinning 
D)  yeast electroporation 
E)  library construction 
A)  prey cloning 
B)  bait cloning 
C)  replica pinning 
D)  yeast electroporation 
E)  library construction

Question 19

Approximately how many unique proteins are produced by a human cell?

Accepted Answer

A)  500 
B)  5,000 
C)  25,000 
D)  50,000 
E)  500,000 
A)  500 
B)  5,000 
C)  25,000 
D)  50,000 
E)  500,000

Question 20

Which of the following limits the utility of yeast two-hybrid screens in identifying protein interactions?

Accepted Answer

A)  Yeast two-hybrid screens can only be applied to bait proteins that are less than 20kDa. 
B)  Only two proteins can be tested for their ability to interact,per day. 
C)  Yeast two-hybrid screens can only find proteins that interact with transcription factors. 
D)  Fusion proteins must be affinity purified. 
E)  Bait proteins may not fold properly when fused to other proteins. 
A)  Yeast two-hybrid screens can only be applied to bait proteins that are less than 20kDa. 
B)  Only two proteins can be tested for their ability to interact,per day. 
C)  Yeast two-hybrid screens can only find proteins that interact with transcription factors. 
D)  Fusion proteins must be affinity purified. 
E)  Bait proteins may not fold properly when fused to other proteins.

Exam 20: Variation and Selection in Populations

Human tears contain approximately 500 different proteins.

How would the results be impacted if a collision cell was not functioning?

Which of the following is not a component of a mass spectrometry system used to identify proteins?

Compare all of the methods of identifying protein interactions in terms of their relative advantages and disadvantages.

You are conducting a yeast two-hybrid experiment to discover proteins that interact with a particular protein of interest (protein X).Which of the following would be a useful step in this process?

Which of the following is not an example of posttranslational modification?

Approximately how many protein coding genes are encoded in the human genome?

The Gal4 DNA binding domain will bind to any eukaryotic promoter.

In a typical yeast two-hybrid experiment,which of the following occurs when bait and prey interact?

In ICAT labelling,heavy and light linkers differ by 8kDa.

Which of these moves most quickly through a mass spectrometer?

In ICAT (isotope coded affinity tag)methods,proteins are labelled with radioactive isotopes.

Which of the following is not directly involved in ICAT (isotope coded affinity tag)labelling and purification?

What is the role of Gal4 in yeast two-hybrid experiments?

Each cell can be considered to have its own proteome.

Which of the following would be required for affinity purification but not for yeast two-hybrid (Y2H)?

What accounts for the differences between the number of protein coding genes in the genome and the number of different proteins expressed?

Which of the following tasks is most often performed by robots during yeast two-hybrid screens?

Approximately how many unique proteins are produced by a human cell?

Which of the following limits the utility of yeast two-hybrid screens in identifying protein interactions?

Mendels Principles of Heredity

Extensions to Mendels Laws

The Chromosome Theory of Inheritance

Linkage, Recombination, and the Mapping of Genes on Chromosomes

Dna Structure, Replication, and Recombination

Anatomy and Function of a Gene: Dissection Through Mutation

Gene Expression: the Flow of Information From Dna to Rna to Protein

Digital Analysis of Genomes

Genome Annotation

Analyzing Genomic Variation

The Eukaryotic Chromosome

Chromosomal Rearrangements and Changes in Chromosome Number

Bacterial Genetics

Organellar Inheritance

Gene Regulation in Prokaryotes

Gene Regulation in Eukaryotes

Manipulating the Genomes of Eukaryotes

The Genetic Analysis of Development

The Genetics of Cancer

Genetics of Complex Traits

Exploring Synthetic Biology: Concepts, Techniques, and Applications

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