Hydrophillic Signals And Transduction Flashcards
What’s hydrophilic definition
A molecule that is attracted to water molecules and tends to be dissolved by water also known as polar molecules
Where to hydrophilic signalling molecules bind to
Transmembrane receptors and do not enter the cytosol
Give examples of hydrophilic signalling molecules
Peptide hormones and neurotransmitters
What do transmembrane receptors do
Change conformation when the ligand binds to the extracellular face. The signal molecules does not enter the cell but the signal is transduced across the plasma membrane
What’s transduction definition
Process by which a chemical or physical signal is transmitted through a cell by a series of molecules events resulting in a cellular response.
How to transmembrane receptors act as signal transducers
By converting the extra cellular ligand binding event into a intracellular signals which alters the behaviour of the cell
What do transduced hydrophilic signals often involve
G-proteins or cascades of phosphorylation by kinase enzymes
What do G-proteins do
Relay signals from activated receptors to target proteins such as enzymes and ion channels
What do phosphorylation cascades allow
Allow more than one intracellular signalling pathway to be activated
What do phosphorylation cascades involve
A series of events with one kinase activating the next in the sequence and so on
What do phosphorylation cascades result in
The phosphorylation of many proteins as a result of the original signalling event
What does binding of the peptide hormone insulin to its receptor do
Results in an intracellular signalling cascade that triggers recruitment of GLUT4 glucose transporter proteins To the cell membrane of fat and muscle cells
What’s step 1 of glucose transporter proteins to the cell membrane
Binding of insulin to its receptor causes a conformational change that triggers phosphorylation of the receptor
What’s step 2 of glucose transporter proteins to the cell membrane
This starts a phosphorylation cascade inside the cell
What’s step 3 of glucose transporter proteins to the cell membrane
This phosphorylation eventually leads to GLUT4-containing vesicles being transported to the cell membrane.
