Sept 6 Flashcards
What are the proteins each for DNA replication, transcription and translation?
There is Dna polymerase for replication, transcription is RNA polymerase, translation is ribosome
What are the 2 genomes we have”?
Have mitochondrial DNA and autosomal and sex chromosome DNA.
Can RNA serve as a functional thing that does not get translated into a protein?
Yes it can function and regulate gene expression
How does nature compensate for females having 2 X chromosomes, why not issues with twice as many genes as men?
It uses dosage compensation, one of the X chromosomes is inactivated in SOMATIC CELLS.
When and how are x-chromosomes inactivated?
Randomly and early in development in somatic cells. In the germ line the inactivated X chromosome is reactivated for oogenesis (formation of gametes)
How was the X chromosome inactivation discovered?
The Barr bodies absorb lots of dye and show up in interphase, highly condensed blob.
How is the X-chromosome inactivated?
The X-inactivating center on chromosome is covered in XIST RNA.
What are techniques to use to find out if X chromosome is inactivated?
Method 1:Label XIST RNA. Method 2: Use CRISPR, and introduce break in dsDNA and introduce a mutation. See the results of mutation if XIST is knocked out. Method 3: use siRNA to knock out XIST, Northern blot shows RNA, or can do qPCR.
What is Klinefelter syndrome
It is many X’s and 1Y, infertile person, low testosterone. More X’s means worse phenotype as only 85% of chromosome genes suppressed so still some build up.
What is the reporter system?
It is a coding region in promotor, and can measure promotor activity with it. Coding parts of DNA are surrounded by switches, and the regulatory molecules bind to switches and recruit RNA polymerase to promotor. Regulatory molecules can be beside or far away from genes.
What is bacteria’s defense against bacteriophages?
They use enzymes that Crispr is based on.
Why type of virus is the lamba virus?
DNA or RNA?
It is a DNA virus.
What is the lytic and lysogenic pathways:?”
Lytic is injected phage DNA, host expresses it and then packages proteins into viral particles, then bacteria burst.
Lysogenic is bacteria harbouring prophage (phage DNA in dormant state).
How does UV light trigger the lysogenic to lytic state?
UV inactivates C1/CI/lambda repressor. This causes the Cro gene to turn on which is needed for the lytic cycle to take place. When lysogenic, Cro is off and C1 is on.
What are control regions within the Lambda phage promotor?
There is Promotor L, promotor RM, and promotor R. When lytic, L and R are turned on, L for N protein and R for cro protein. When lysogenic, only Rm is on which turns on C1 gene, suppresses activation of prophage and other phages infecting lysogen.
