Transcription Flashcards
what does RNA contain instead of a deoxyribose
ribose
what is the structure of RNA
single stranged
what is transcription catalyzed by
RNA polyermase
what does RNA polyermase do
moves along templant DNA and unwinds it. Also catalyzes formation of phosphdiester bonds increasing the length of RNA polyer
difference between RNA polymerase and DNA polymerase
RNA polymerases initate RNA synthesis without a primer. more error prone
RNA polyermase used in mRNAs
POl II
RNA polyermase unsed in rRNAs
Pol I mainly, some Pol III
RNA polyermase used in tRNAs
pol III
RNA polyermase used in snoRNAs
pol II
RNA polyermase used in other non-coding RNAs
pol III and II
function of rRNA
components fo ribosome that are required for protein synthesis
function of tRNA
serve as adapters between mRNA and amino acids during protein synthesis
function of snRNAs
serve a number o ffunction in the nucleus, including pre-mRNA splicing
function of snoRNAs
process and modify rRNAs
what is the most abundent RNA in the cell
rRNA
how is tRNA molecules synthesized
larger precurosor molecules are trimmed and chemically modified
how does pol II know where to start
promoter region of DNA
what is common in promoter regions
consensus DNA
consensus sequence
sequence is similiar but not necessarily identifcal
examples of consensus sequres
TATA box, CAAT box, GC region
what consensus sequence is alomst always found in genes transcribed by Pol II
TATA box
does pol II requre transcription factors in order to initiate transcription
yes
function of TBP portion of TFIID
binds to TATA box, acts as a signpost
what base pairs are easier to pull apart
A-T
what are promotor regions usually rich in
AT pairs
basal transcription complex
compex of RNA and general transcription factors
function of basal transcription complex
initiates transcription at low rate
what do GC-rich sequences bind
SP-1
what does CAAT box bind
NF1
function of enchanger elements
proteins bind here and stimulate transcription a great deal
what is a prerequisite to transcription
extensive chromatin remodeling
toxin found in death cap mushroom
alpha-amanitin
how does alpha-amnitin work
inhbitor of Pol II
what happens when you inhibit pol II
block synthesis of mRNA
how does rigampicin work
potent inhibitor of RNA polyermase
does rifampicin affect eukaryotic pol II
no
what do you use rifampicin for
TB
