Test gene regulation brainscape Flashcards
What is the role of gene regulation in development?
Gene regulation is crucial as totipotent cells become pluripotent and then differentiate into unipotent cells.
How does regulating the synthesis of primary transcripts affect gene expression?
Regulating the synthesis of primary transcripts ensures that everything downstream is also regulated.
What are upstream regulators?
Upstream regulators modulate activity with enzymes, transcription factors (TFs), co-repressors, and co-activators.
What is a nucleosome?
A nucleosome consists of a protein octamer (H2A, H2B, H3, H4) x2 and 146 bp of DNA.
What characterises euchromatin?
Euchromatin is loosely packed, allowing transcription factors to bind and transcription to be active.
What characterises heterochromatin?
Heterochromatin is densely packed, preventing transcription factors from binding and initiating transcription.
What are epigenetic modifications?
Epigenetic modifications alter chromatin state via DNA methylation and histone modifications.
What is the function of a promoter?
The promoter is located immediately upstream of the 5’ end of a gene and is the site for transcription initiation.
What is the TATA box?
The TATA box is a site for binding TATA-binding protein (TBP), which initiates transcription.
What are enhancer and silencer regions?
Enhancers and silencers are distal regulatory regions that can be located on different chromosomes and bind multiple activators and repressors.
What do general transcription factors do?
General transcription factors form a pre-initiation complex by binding to the promoter.
What is RNA polymerase II responsible for?
RNA polymerase II transcribes mRNAs, miRNAs and some small nuclear RNAs (snRNAs).
What does RNA polymerase I transcribe?
RNA polymerase I transcribes ribosomal RNA (rRNA).
What does RNA polymerase III transcribe?
RNA polymerase III transcribes transfer RNA (tRNA) and 5S RNA.
