epigenetics Flashcards
what’s the basic of epigenetics
changes in gene expression with no relation to DNA sequence
what can epigenetics determine
the likelyhood of a gene being more expressed or silenced
what types of epigenetics are there
- DNA methylation
- histone modification
describe what DNA methylation is
the addition of a methyl group to a specific base in a DNA sequence that doesn’t let the base be transcribed
how does methylation occur
dependent n the biochemical environment surrounding it
if a bees isn’t methylised then the surroundings have correct biochemical environments for that protein
what does DNA methylation explain
how organs have cells specifically tailored to them and their function
- every cell in that organ has the same base or sequence methylised or silenced compared to another organ cell
the methylisation can also be spread through mitosis so explains why organ cells only divide into their specific organ cells and not a random other one (unless biochemical or mutations occur)
how long/ damaging is DNA methylation
long term/ permanent
what is histone modification
the way the histone is modified depends on t=if the dna can be transcribed or not (limits aceylation)
if the histone as an acetyl group attached the DNA isn’t tightly coiled so it can be transcribed
what does histone modifcation do to transcription
limits the amount of aceylation that can occur to each histone so limits the transcript ability of each protein
