Chapter 19 - Control of Gene Expression in Eukaryotes Flashcards
Where is DNA usually methylated?
cytosines located next to guanines
What is responsible for the inactivation of one X chromosome in females?
DNA methylation
What does the HAT enzyme do?
Acetylates histones
What does the HDAC enzyme do?
De-acetylates histones
What does methylation do?
It can activate or deactivate gene expression
What type of differential gene expression are epigenetic changes?
Chromatin Remodelling
What are the two kinds of transcription factors?
Basal transcription factors (binds to promotor)
Regulatory Transcription factors (bind to control elements)
Where does the RNA polymerase bind?
Core promotor
Promotor-proximal Control Elements
Has sequence unique for its gene.
Silencers
Opposite to enhancers - repressors bind to silencers and stop transcription
What’s the difference between transcription factors and control elements?
Transcription factors are proteins and control elements are DNA sequences
microRNA
miRNA binds to RISC protein complex and complementary strands of RNA. RNA is degraded or held in place to stop transcription
RISC Protein Complex
Complex that miRNA binds to in order to stop mRNA from being translated
Proto-ocogenes
genes that stimulate cell growth
Transcription Factor p53
tumour suppressor, guardian of the genome
