Epigenetic Control of Gene Expression (AQA A-Level Biology): Flashcards

Heritable changes in gene function without altering DNA sequence

Chemical modifications on DNA & histones determining gene access

Loosely packed chromatin, DNA accessible, genes switched on

Tightly packed chromatin, DNA inaccessible, genes switched off

Histones more +ve charged, stronger DNA attraction, genes inhibited

Methyl groups ($ext{CH}_3$) to cytosine bases in DNA

Blocks transcription factors; attracts deacetylation proteins

Abnormal patterns activate oncogenes or silence tumour suppressors

Demethylating drugs & histone deacetylase inhibitors

Uses siRNA to break down specific mRNA before translation