endocrine Flashcards
what amino acid is metabolized into seratonin and melonin
tryptophan
which amino acid is metabolized into norepinephrine, epinephrine and dopamine
tyrosine
what happens when the GPCR binds a water soluble protein and changes conformation
alpha subunit binds GTP and leaves complex to bind effector protein
two most famous effector proteins of GPCR system
adenylate cyclase and phospholipase C
what happens to alpha subunit after it activates effector protein
rejoins beta and delta subunits of GPCR
what does adenylate cyclase do (2 steps)
converts ATP to AMP which activates a kinase
how is cAMP inactivated
phosphodiesterase
what step follows the activation of phospholipase C
phospholipase C catalyses break down of phosphotidylinositol biphosphate (PIP2) into diacylglycerol(DAG) and inositol triphosphate (IP3).
name the three secondary messengers we discussed
diacylglycerol (DAG), inositol triphosphate(IP3), and cAMP
effect of DAG
DAG activates protein kinase C
effect of IP3
opens Ca channels of SR to contract muscle
When a hormone requires the simultaneous or previous exposure to another hormone
permissive effect/interaction
When the effect of two hormones is greater than the effect of each of the hormones individually
synergistic effect/interaction
This tends to occur when there has been prolonged exposure to the hormone
down regulation
a brief response when there is overstimulation of a receptor (terminates when the agonist concentration returns to normal)
desensitization -Phosphate detaches the recptof from membrane proteins
