BIOLOGY 2B03 Lecture Notes - Lecture 15: Phosphorylase Kinase, Protein Kinase A, Phosphodiesterase
Document Summary
7 tra(cid:374)s(cid:373)e(cid:373)(cid:271)ra(cid:374)e - helices that loop through membrane. The -helices create 4 extracellular segments (e1- E4) which create an extracellular signal binding pocket. The -helices create 4 cytoplasmic segments (c1-c4) which forms an internal domain which interact with a trimeric g-protein. Catecholamines: water-soluble signals that circulate bloodstream and includes epinephrine (adrenaline), norepinephrine (noradrenaline) and dopamine. Epinephrine and norepinephrine are released by adrenal medulla. The receptor for these signals is a gpcr which activates the receptor-associated trimeric g- protein activates an effector protein called adenylyl cyclase modulates levels of secondary messenger called camp. Epinephrine can bind to both of these receptors, but it will induce a different response and this is why the same signal can induce many different responses in the different tissues of the body: -adrenergic receptors are. It overall increases blood supply and energy supply in body while reducing unnecessary expenditures of energy such as in intestines: 2-adrenergic receptors are inhibitory.
