7.2.1 - Transcription factors Flashcards
What is the name of the compounds that control the transcription of genes?
Transcription Factors
What is the first step in the transcription of genes?
Activator proteins bind to enhancers/promoters.
This causes DNA to bend bringing them near a gene promoter.
What happens in the transcription of genes when an activator protein has binded to enhancers?
Other transcription factor proteins join to the activator proteins, forming a protein complex which binds to the gene promoter.
What happens in the transcription of genes when a protein complex has been formed?
The protein complex makes it easier for RNA polymerase to attach to the promoter and start transcribing a gene.
What do insulators do in gene transcription?
Stop the enhancers binding to the promoter
What is methylation in gene transcription?
The addition of a methyl group to the C nucleotides, allowing enhancers to bind to the promoter
What are transcription factors?
Proteins that bind to DNA and affect the process of transcription
Where are promoters found?
The start of the target gene
What to activators do?
Help RNA polymerase bind to the start of the target gene and activate transcriptions.
What do repressors do?
Inhibit or decrease the rate of transcription by preventing RNA Polymerase from binding to the target gene, therefore stopping transcription
Describe what happens to the DNA when transcription factors bind.
They create a loop in the DNA molecule that activates the gene.
This allows RNA polymerase to attach to the DNA chain and transcription will start.
Give 2 examples of transcription factors.
Oestrogen
RNAi
How does Oestrogen work?
It can affect transcription by binding to a transcription factor.
The transcription factor is the Oestrogen receptor.
This then moves to the nucleus where it binds to the promoter region before the target gene.
This then acts as a promoter
What is the function of the Oestrogen receptor?
Regulates gene expression events that culminate in cell division
