RNA and transcription W4 Flashcards
three main differences between RNA and DNA
RNA is single stranded
it contains Uracil instead of thymine
it contains ribose instead of deoxyribose
three main RNA species
messenger RNA (mRNA) ribosomal RNA (rRNA) transfer RNA (tRNA)
primary role of mRNA
directs amino acid sequence for proteins
primary role of tRNA
transports amino acids to site of protein synthesis
primary role of rRNA
part of ribosome, involved in protein synthesis
how is RNA made
via RNA polymerase
what directs the transcription process
DNA sequence
what is a promoter
start signal - TATA box: 5’TATAAA3’
what is the start signal recognised by
TATA protein (TBP)
what is the terminator
stop signal- 5’ AATAAA 3’ signals polymerase to stop
what controls the rate of transcription
transcription factors
what do transcription factors do
regulate the rate of transcription
how do transcription factors regulate the rate of transcription
by binding to specific DNA sequences in promter regions (DNA BINDING DOMAIN) and interract with proteins that are required for transcription to alter rate (ACTIVATION/REPRESSION DOMAIN)
what are the two types of transcription factors
general
specific
what is the difference between general and specific transcription factors
general - needed for transcription to occur, same ones required for all genes and cells
specific- not needed for transcription to occur, but they increase/decrease the rate`