Chapter 19 Flashcards
gene expression is regulated in ______ levels (eukaryotic version)
several
what are the three controls for DNA in eukaryotic organisms
transcriptional control, transcriptional control, and post translational control
what are the steps in transcriptional control?
DNA to pre-mRNA
epigenetic regulation
transcriptional initiation
what are the steps from pre-mRNA to protein?
mRNA stability
RNA interference
translational regulation
what are the steps in post-translational control?
Post-translational modifications
what is the full process of gene expression in Eukaryotic organisms?
nucleus
1. chromatin remodeling
2. transcription
3. RNA processing
cytoplasm
4. mRNA stability
5. translation
6. post-translational modification
what does epigenetic mean?
on top of genome
what are the three types of epigenetic regulation?
DNA methylation, histone modification, and noncoding RNA action
what is a chromatin?
DNA and its associated proteins
what is a nucleosome?
group of histones
what is a histone?
(+) group of proteins that bind to DNA
why does condensed chromatin not get transcribed?
there is no space for the proteins needed for transcription
why does decondensed chromatins get transcribed?
there is space for the proteins needed for transcription
what was condensed and decondensed chromatins treated with to see if they were degraded?
DNase 1
how does covalent modifications of histones impact chromatin structure?
HAT adds lysines to the histone. this neutralizes the positive charges and weakens the affinity for DNA
HDAC takes the lysine off
how does DNA methylation inhibit transcription?
H3C (methane) is added where there is a CG island
methylated cytosine is not transcribed because the proteins can not bind
how does the chromatin remodeling complexes make specific DNA regions more accessible?
it repositions nucleosomes after other larger modifications have already been made
are epigenetic modifications inherited?
they can be
how are epigenetic modifications inherited?
made and then maintained through meiosis
