1.4b - Hydrophobic Signals and Control of Transcription Flashcards
Hydrophobic signalling molecules can diffuse…
through the phospholipid bilayers of membranes, and so bind to intracellular receptors
The receptors for hydrophobic signalling molecules are…
transcription factors
Transcription factors are proteins that…
when bound to DNA can either stimulate or inhibit initiation of transcription
2 examples of hydrophobic signalling molecules
oestrogen and testosterone (steroid hormones)
Steroid hormones bind to…
specific receptors in the cytosol or nucleus
The hormone-receptor complex moves to…
the nucleus where it binds to specific sites on DNA and affects gene expression
The hormone-receptor complex binds to…
specific DNA sequences called hormone response elements (HREs)
Binding at HREs influences…
the rate of transcription, with each steroid hormone affecting the gene expression of many different genes
