Transcription factors Flashcards
1
Q
what are transcription factors?
A
- proteins that control the rate of protein synthesis
2
Q
How do transcription factors achieve their role?
A
- By switching some genes on and some genes off
3
Q
What is the promoter region?
A
- short sequence of DNA at the start of a gene (the bit that DNA/RNA polymerase attach to)
4
Q
What are two transcription factors?
A
- activator
- repressor
5
Q
what happens during transcription?
A
- Transcription factor moves from the cytoplasm into the nucleus
- binds to the promoter region
- activators - helps RNA polymerase to bind to DNA
- gene is transcribed
- Repressors - prevent RNA poymerase binding to DNA
- gene is not transcribed
6
Q
what do the activators do?
A
- helps RNA polymerase bind to DNA
- gene is transcribed
7
Q
what do the repressors do?
A
- prevents RNA polymerase binding to DNA
- gene is not transcribed
8
Q
Give an example of controlling a transcription factor?
A
- Oestrogen
9
Q
What is Oestrogen?
A
- a steroid hormone
10
Q
How is oestrogen controlled as a transcription factor?
A
- oestrogen binds to a receptor called an oestrogen receptor
- forms an oestrogen- oestrogen receptor complex
11
Q
Is oestrogen an activator or repressor?
A
- This can depend on the cell
12
Q
what can transcription factors be turned on/off by?
A
- second messengers
- e.g cAMP
