1.3 Flashcards
describe what full agonist is?
has 100% efficacy
provokes biological response
describe what partial agonist is?
less than 100% efficacy
describe what natural antagonist is?
has 0% efficacy but occupies a receptor site
blocks
describe what inverse agonist is?
binds to receptor and produces opposite effect of an agonist
which molecules act as molecular switch?
ATP
GTP
what removes the GDP from inactive G-proteins?
GEF (Guanine Exchange Factor)
what stimulated the G protein intrinsic GTPase activity?
GAP (GTPase Activating Protein
example for first massenger?
NE
NeuroTransmitters
5 Receptor types:
- GPCR
- Ion channels
- Receptor with enzyme activity
- Enzyme Activity- Linked Receptor
- Intracellular Receptors
GPCR structure
7TM domains
heterotrimeric (a,b,gamma)
a subunit of GPCR binds
GDP or GTP
what happens when the a subunit binds GTP?
a subunit dissociates from the beta-gamma complex
what breaks down cAMP?
phosphodiesterase
caffeine blocks it
Gi GPCR effects
inhibitory- opposing Gs activity
Phospholipase A2 active -> arachidonic acid release -> COX -> bla bla bla
Gq GPCR effects
stimulates Phospholipase C -> converts PIP2 to IP3 and DAG
DAG activates:
PKC -> phosphorylation of stuff
IP3 will cause:
sarcoplasmic reticulum and ER to release Ca++
what will happend once Ca++ binds Calmodulin
they can bind CaM dependent kinase which will phosphorylates Myosin Light Chain Kinase, which initates smooth muscle contraction
effects of G12/13 GPCR
regulates GEF
activates Rho small G proteins
activates Rho Kinase
Excitatory Ion channel Receptor and their ligands
- Nicotinic (ACh)
- NMDA (Glu)
- AMPA (Glu)
- 5HT3 (Serotonin)
Nicotinoc ACh Receptor is
ionotropic
what is the inhibitor for nicotinic ACh R in the muscle?
curare
muscarinic ACh R are inhibited by
Atropin
examples for receptor tyrosine kinase?
GF
Insulin
steps in receptor tyrosine kinase activation?
ligand binding receptor dimerize autophosphorylation SH2 domain GRB2 -> SOS Ras-GDP -> Ras-GTP MAPK (mitogen activated protein kinase) **also inhibirion of apoptosis
anouther example for receptor with enzyme activity?
Guanylyl cyclase receptor
example for Guanylyl cyclase receptor lignad
ANP
action of Guanylyl cyclase receptor
ANP binds receptor
GTP -> cGMP
cGMP activated PKG -> vasodilation
action of enzyme activity linked receptors?
JAK -> STAT
