Hydrophobic Signals And Control Of Transcription Flashcards
What are hydrophobic molecules
Molecules that are seemingly repelled by a mass of water also known as non polar
What can hydrophobic signalling molecules do
Can diffuse directly through the phospholipid bilayer so f membranes and so bind to intracellular receptors
What are intracellular receptors In hydrophobic signalling molecules
Transcription factors
What are transcription factors
Proteins that when bound to DNA can either stimulate or inhibit initiation of transcription
What are examples of hydrophobic signalling molecules
Steroid hormones oestrogen and testosterone
What do steroid hormones do
Bind to specific receptors in the cytosol or the nucleus
What does the hormone receptor complex (HRC) do
Moves to the nucleus where it binds to specific sites on DNA and affects gene expression
What do HRC bind to
Specific DNA sequences called HRE’s.
What does binding at HRE’s sites do
Influences the rate of transcription with each steroid hormone affecting the gene expression of many different genes
Why do steroid hormones not require a membrane bound receptor
These receptors are transcription factors
