Hydrophilic, cannot cross plasma membrane or enter the cell
Extracellular receptors
Hydrophobic, can cross the membrane
Intracellular receptor
Recognition of ligand by receptor is aided by…
transfer and transmission by signaling molecules
GDP - signal is on or off?
OFF
GTP - signal is on or off?
ON
What does the GEF do?
Swaps GDP for GTP, activating GTPase
What does GAP do?
Speeds up hydrolysis of GTP, ending GTPase activity
What are the three classes of receptors
Ion channel - coupled receptor, G-protein-coupled receptors, Enzyme-coupled receptors
Ligand binds, opens and closes channel
Ion channel-coupled receptor
associated with GTP (on), GDP (off), includes adrenalin, serotonin, histamine, dopamine
G-protein-coupled receptor
Receptor is coupled to an enzyme, usually a kinase or receptor is an enzyme, usually a tyrosine kinase
Enzyme-coupled receptor
What 2 pathways are activated when an enzyme-coupled receptor is activated
Ca2+ and phospholipase C + RAS and MAP kinase
Why is HAT important in initiating transcription
It opens the chromatin, makes in accessible
What are the 2 pathways that could be activated on GPCR-ligand bindings
Phospholipase C to PKC, Adenylate Cyclase to Protein Kinase A
