Dynamics Flashcards
who have affinity to receptors agonist or antagonist
both of them
Receptor
mediated “4”
1
. Ligand gated ion channels fast neurotransmitters)
3
. Receptors Linked to Tyrosine Kinase Enzymes
2
. G protein Coupled Receptors slow neurotransmitters)
4
Intracellular Receptors Regulating
Transcription very slow)
Ligand gated ion channels eg.
cholinergic nicotinic receptors
G protein Coupled Receptors
alpha and beta adrenoreceptors
Receptors Linked to Tyrosine Kinase Enzymes eg.
insulin receptors
Intracellular Receptors Regulating
Transcription
steroid receptors
what happens to the muscke when Na+ influx due to stimulation of ligand gated ion channel
depolarization skeletal muscle contraction
types of G protein receptors
Gs, Gi, Gq
what does G protein consists of
protein is a trimer (α, β and γ).
movable and fixed parts in G protein
β
and γ are fixed in cell membrane. But α subunit move
when we can say that G protein is active
when GDP is GTP
What is the sequence of Gq?
GDP→GTP activates enzyme PLC “phospholipase C” on cell membrane →breaks PIP2 to DAG and IP3
DAG activates PKC
IP3 activates Ca influx from SR “sarcoplasmic reticulum”
What is the sequence of Gs?
GDP→GTP activates adenylyl cyclase converts ATP→cAMP which activates PKA which phosphorylates
What is the sequence of Gi?
GDP→GTP inhibits adenylyl cyclase which inhibits PKA which and inhibit phosphorylation
which enzyme activates in Gq
PLC and PKC
