Transcriptional Factors Flashcards
What can stimulate or inhibit the transcription of genes?
transcriptional factors moving from the cytoplasm into the nulceus
What enables a cell to be specialised?
certain genes being switched on/off so only certain genes are transcribed and proteins produced
What type of molecule are transcriptional factors?
proteins
How do transcriptional factors stimulate transcription?
specific shape part of the protein binds to specific DNA sequence that they are complementary to so can initiate transcription
What happens after transcriptional factors bind to the DNA?
it allows RNA polymerase to bind
What are the 2 parts of transcriptional factors?
receptor and DNA bind site
What happens if transcriptional factors do not bind?
the gene is inactive and proteins will not be made
What is oestrogen?
a steroid hormone that can work with transcriptional factors to initiate transcription
How does oestrogen initiate transcription?
binds to the receptor site on the transcriptional factor
How does oestrogen binding to the receptor allow transcription to occur?
changes the shape of the DNA binding site, making it complementary and able to bind to the DNA
What allows oestrogen to enter a cell?
it is lipid soluble so can diffuse through cell membranes
How do activated transcriptional factors enter the nucleus?
through nuclear pores
Why can RNA polymerase only attach after transcriptional factors have attached?
as it is a protein, so has a specific tertiary structure and active site that is complementary in shape to the DNA and transcriptional factor TOGETHER
What are transcriptional factors an example of?
gene regulation
When does transcription occur?
when a molecule from the cytoplasm a
enters the nucleus and binds to the DNA
