NR 565 week 1 notes.

Agonist- ia idrug ithat ibinds ito iand iactivates ia ireceptor. iCan ibe ifull, ipartial ior iinverse. iA ifull iagonist ihas ihigh iefficacy, iproducing ia ifull iresponse iwhile ioccupying ia irelatively ilow iproportion iof ireceptors. iA ipartial iagonist ihas ilower iefficacy ithan ia ifull iagonist. iIt iproduces isub-maximal iactivation ieven iwhen ioccupying ithe itotal ireceptor ipopulation, itherefore icannot iproduce ithe imaximal iresponse, iirrespective iof ithe iconcentration iapplied. iAn iinverse iagonist iproduces ian ieffect iopposite ito ithat iof ian iagonist, iyet iit ibinds ito ithe isame ireceptor ibinding-site ias ian iagonist. Antagonist- ia idrug ithat iattenuates ithe ieffect iof ian iagonist. iCan ibe icompetitive ior inon- icompetitive, ieach iof iwhich ican ibe ireversible ior iirreversible. iA icompetitive iantagonist ibinds ito ithe isame isite ias ithe iagonist ibut idoes inot iactivate iit, ithus iblocks ithe iagonist’s iaction. iA inon- icompetitive iantagonist ibinds ito ian iallosteric i(non-agonist) isite ion ithe ireceptor ito iprevent iactivation iof ithe ireceptor. iA ireversible iantagonist ibinds inon-covalently ito ithe ireceptor, itherefore ican ibe i“washed iout”. iAn iirreversible iantagonist ibinds icovalently ito ithe ireceptor iand icannot ibe idisplaced iby ieither icompeting iligands ior iwashing.