Transcription Factors

Question 1

What is a promoter region?

Answer 1

A specific sequence of bases that are complementary to the transcription factor

Question 2

How is transcription stimulated to form a protein?

Answer 2

• inhibitory molecule detaches from the transcription factor, exposing the binding site
• the transcription factor moves from the cytoplasm into the nucleus and binds to the DNA at the promoter region which is upstream of the gene
• this activates transcription when RNA polymerase is activated forming mRNA, which is then translated at a ribosome to make a protein

Question 3

What is the effect of oestrogen on transcription?

Answer 3

• oestrogen is lipid soluble so can cross the phospholipid bilayer by diffusion and binds to a specific oestrogen receptor protein on the inhibitor molecule
• this causes the inhibitor molecule to detach and the oestrogen receptor/transcription factor complex moves into the nucleus
• the transcription factor binds to DNA at the promoter region and this stimulates the gene downstream to undergo transcription due to the activated RNA polymerase