Transcription - Lecture 6 Flashcards
What is Transcription?
TRANSCRIPTION is the process of making a copy of genetic information stored in a DNA strand into a completemary strand of mRNA with the air of RNA polymerase .
What are the three steps of Transcription?
Initiation
Elongation
Termination
What occurs in the initation of Transcription?
RNA polymerase binding
DNA chain separation
Transcription Initiation
What occurs in the Elongation phase of transcription?
RNA polymerase and Transcription factor move along the DNA
Addition of mRNA
Rewinding of DNA as the RNA and Transcription factor moves past
What occurs in the Termination phase of transcription?
Release of the final finished chain of mRNA (Transcript)
Where does Transcription begin?
Transcription starts at Nucleotide + 1
Where does RNA polymerase bind on the gene?
Binds to the Promoter region
- Very specific sequence of nucleotides within the DNA
What is the TATA box?
The TATA box is found in all promoters
It is recognised by Pol II
It tells Poll II to start transcribing and in what direction
What RNA Polymerase is stimulated by the TATA box?
Pol II
What is the Tata Binding Protein?
This is a protein that recognises the TATA box and forms a landing platform for all other transcription factors
What is a general transcription factor required for all transcription reactions involving Pol II?
TFIID (TF2D)
What helps determine the transcriptional start and direction for Pol II?
TF2D introduces a kink into the DNA
What starts Transcription initiation?
Require additional General Transcription Factors
TF2D remains at the promoter region for new initiation complexes to form
What allows transcription at low basal rates?
TF2D remains at the a promoter region for initiation of new complexes to form
What direction is the RNA chain synthesised ?
5’ - 3’
