<prompt> True statement regarding inverse agonists is-Binds to receptor and causes intended actionBinds to receptor and causes opposite actionBinds to receptor and causes no actionBinds to receptor and causes submaximal action  <response>: Ans. is b i.e., Binds to receptor and causes opposite action o Receptors are specific binding site with functional correlate,o In relation to action through receptors, two terms are important.i AffinityAbility of the drug to combine with the receptor.It determines the concentration of drug required to form a significant number of drug-receptor complexes.ii Intrinsic activity efficacyAbility of the drug to activate induce a conformational change in the receptor.Based on their intrinsic activity drugs may be divided in to :AgonistAntagonistPartial agonistInverse agonist---Have both affinity and maximal intrinsic activity.Have affinity but no intrinsic activity.Have affinity and submaximal intrinsic activity.Have affinity but opposite intrinsic activity ie intrinsic activity with a minus sign. AgonistAntagonistPartial AgonistInverse Agonist---Affinity Intrinsic Activity Affinity Intrinsic Activity 0Affinity - Intrinsic Activity 12 Affinity Intrinsic Activity - 