Genomic Regulation Flashcards
Nucleus is the site of what?
Cell regulation
Proliferation
DNA transcription
HIV a ___ virus, affects what step in the central dogma of genetics?
RNA virus
Transcription - specifically reverse transcriptase
DNA is ___ and ___. Meaning the 5’ side faces the 3’ side and go in opposite directions
Double stranded
Anti-parallel
Pure (AG) Agriculture
What is this pneumonic for
Purines are AG, pyrimidines are TC
A ___ T
G ___C
A double bonds t
G triple bonds C
So GC is a stronger bond
What type of bond is formed btwn the histone octamer and DNA in each nucleosome?
Histone proteins are highly ___ across species.
142 H-bonds
also:
hydrophobic interactions
salt linkages
conserved, don’t change (2 AA change btwn pea and cow histone)
What AAs make up 20% of hisotne proteins?
Lysine, Lys, K
Arginine, Arg, R
Post translational modifications (PTMs) target what residue on histone proteins?
lysosome
parts of the histone octomer?
2 of H2Ax H2B
2 of H3 x H4
These make a ball, with a stick looking thru it:
H1
Proteins that bind to DNA are either histone proteins or ___. A nucleosome core is made of ___ histone proteins.
Protein + DNA = ___
non-histone chromosomal proteins (TFs)
8
Histone octomer is the protein (spool) the DNA winds around (thread)
Chromatin
Euchromatin vs. Heterochromatin
Euchr: LIGHTLY packed, under more transcription, more acitive part of genome, 92% of human DNA
Hetero: CONDENSED, late replicating/genetically inactive, centromeres and telomeres highly concentrated, contain few genes**
How can genes on heterochromatin be more active?
Position effect
gene activity depends on relative position and can be silenced even if they were actively expressed if moved to heteroch.
DNA that doesn’t contain genes
regulatory info, “junk” DNA (even though now they are now discovering they DO have a purpose
who first used the word gene? this was based on who’s concept
gene—> Wilhelm Johannsen based on Gregor Mendel’s concept
Watson anc crick double helicase of DNA what yr?
Nirenber, Khoranna, Holley determined genetic code?
Feb 2001 human genome announced? finished?
1953
1966
2001 announced
2003 finshed ( slide says 2004)
What are CGH arrays?
Comparative Genome Hybridization which helps us detect CNVs
Copy Number Variations (CNVs) are in the thousands, which brings rise to disease states
RNAi is a biological process in which ___ molecules inhibit ___ expression or translation.
RNA molecules (miRNA) It neutralizes targeted mRNA molecules
What are LTRs?
Long terminal repeats
ID sequences of DNA, formed by reverse transcription of retroviral RNA and viruses to insert their genetic material
Explain the order of miRNA
- microRNA (miRNA) folds on itself
- Dicer goes down double stranded RNA, cutting it into shorter segments
- one strand of miRNA associates with a protein complex, and teh bound miRNA base pairs with target miRNA taht has compelementary seq.
miRNA-protein complex prevents gene expr.
how does the miRNA protein complex prevent gene expression?
- degrading target mRNA
2. blocking its translation
Introns begin with ___ and end with ___
GT
AG
Histone deacetylase (HDAC) does what
actively represses gene expresseion, by having it be compact and transitionally repressed (beads are wound tight on teh string)
Histone acetylation (HAT)
promotes gene expression, ithe chromatin is open and transcrptionally active (beads are wound looely on the string)
