Flashcards in Gene regulation in eukaryotes Deck (11):
what is the structure of chromatin?
DNA wrapped around histones and joined together to form nucleosomes which join together to from chromatin
describe features of heterochromatin
amino acids in histones give off positive charge so the negatively charged DNA tightly binds making it inaccessible for transcription
describe features of euchromatin
lightly packed chromatin
acetyl group neutralises histones positive charge
what is the inactive state of transcription?
RNA polymerase isn't bound to the tightly packed chromatin - no phosphorylation
what is the paused state of transcription?
RNA polymerase and transcription factors are bound to promotor but remain inactive - single phosphorylation
what is the active state of transcription?
more transcription factors bind and RNA polymerase becomes phosphorylated
what is RNA processing?
the addition of caps turns pre-mRNA into mature mRNA and introns are spliced out
what are 2 types of small RNA?
- small interfering RNA
- micro RNA
what does siRNA do?
Repression of gene transcription via chromatin remodelling and DNA methylation
what does miRNA do?
- repression of gene translation
- promotes mRNA degradation