Turning Off the Signal

Question 1

In Situ

Answer 1

mRNA can be detected with a complimentary probe that has a florescent tag on it

Question 2

In Situ Hybridization

Answer 2

-probe will bind or hybridize in a complementary fashion to the target mRNA molecule

Question 3

Reverse Transcriptase

Answer 3

allows the reversal of transcription

Question 4

DNA Microarray Techniques

Answer 4

made it possible to examine the expression of thousands of genes at once
-base pair interactions bind complementary strands of nucleic acids

Question 5

Protein Stability

Answer 5

• post-translation modifications such as cleavage, phosphorylation and methylation occur
• modifications allow the cell to activate/inactivate specific proteins

Question 6

SiRNAs

Answer 6

small interfering RNAs

Question 7

mRNA Stability

Answer 7

• to stop gene expression, mRNAs should be degraded

- a way to regulate mRNA stability is the length of the poly A tail

Question 8

How mRNA is destabilized

Answer 8

SiRNAs are processed and associated with RISC complex

-induce cleavage of target mRNA which destabilizes the target mRNA

Question 9

Selective Degradation

Answer 9

can limit the time a protein functions in a cell

Question 10

Proteasomes

Answer 10

very large protein complexes that can break down peptide bonds resulting in them degrading unneeded or damaged proteins

Question 11

How can proteasomes regulate the concentrations of specific proteins?

Answer 11

-by breaking long polypeptides into small amino acids

Question 12

Tagging Method

Answer 12

• tagging is used to identify proteins for degradation
• tagging process is ATP dependent and is facilitated by ubiquitin activation conjugation to target substrate protein and ligation
• results in a polyubiquitin chain which allows the proteasome to degrade the tagged protein

Question 13

Ubiquitin Proteins

Answer 13

tag the target proteins