regulation of transcription and translation

how does adrenaline operate

using a second messanger

describe how transcription is controlled

• the gene is switched on by transcriptional factors

• each transcriptional factor has a site that binds to a specific base sequence of dna, this causes this region of dna to begin transcription

• mrna is produced and the information it carries is translated into a polypeptide

• when the gene is not expressed the transcriptional factor that binds to dna is inactive

• so transcription and translation is stopped

what can oestrogen do

Switch on gene to start transcription by combining with a receptor site on a transcriptional factor, this activates the dna binding site to change shape

Describe the effect of oestrogen on gene transcription

• lipid soluble so diffuses through phospholipid bilayer

• oestrogen binds with a receptor site on transcriptional factors each (complementary)

• changes shape of dnas binding site on transcriptional factor so can bind to dna

• the transcriptional factor can enter nucleus through nuclear pore, bind to specific base sequences on dna