Hydrophobic Signals and Control of Transcription Flashcards
How does signaling work?
Each specific protein signal sent has a specific receptor, which upon binding will have a conformational change which in turn passes the message on
What types of cell need signalling and what type of signalling do they use??
Multicellular organisms have to signal information to other cells by using extracellular signals
Describe the solubility of a fatty acid on the phospholipids
They fatty acid tails of the phospholipids are hydrophobic. this feature allows other hydrophobic molecules to pass through easily
What can a hydrophobic signalling molecule do?
Diffuse through the cell membranes
What can hydrophobic signalling molecule do once in the cell?
It can bond to a receptor molecule that allows them to have a direct effect on transcription in the nucleus
What is thyroxine and what does it help to regulate?
Thyroxine is a hormone that is involved in controlling the rate of cell metabolism
What type of signalling molecule is Theyroxine?
I tis a hydrophobic signalling molecule that binds to a receptor molecule in teh cytoplasm
What happens when thyroxine binds to a receptor molecule?
In doing so it stops the receptor molecule from binding to a section of DNA that controls the transcription of Na/K-ATPase gene. This then allows transcription to take place
What happens when thyroxine is not present?
When thyroxine is not present the receptor binds to the section of DNA controlling the transcription of Na/K-ATPase stopping transcription from taking place
What type of signalling molecules is a steroid?
Steroids are also hydrophobic signalling molecules
What do steroids do?
They can pass through cell membranes before they bind to a specific receptor protein in the cytosol or nucleus know as a transcription factor
What happens once the steroid has binded to the receptor protein?
Once the steroid binds to the transcription factor it can then bind to gene regulatory sequences on the DNA and control the transcription of specific genes
Give two examples of steroids
Testosterone
Oestrogen
