*ON EXAM* Describe the Scatchard Plot of Binding Data (Rosenthal Plot) B_max = [R]_TOT = total bound receptor concentration	Describe the Effect (dose-response) vs. Agonist Concentration curves. Where are E_max and EC₅₀ for both curves? What is the benefit of this graph? Provides insights into biological response/function induced! Unlike [AR] bound vs. [A] graph which only tells use the binding affinity and not biological effects.	Describe the process of determining affinity of drug for receptor and receptor density of tissue (total binding, non-specific binding, specific binding)
If a receptor subtype has no intrinsic activity, then an inverse agonist is likely to behave as a _____ _____ Competitive antagonist	K_d and affinity of drug for receptor are _____ correlated Inversely	Measuring Ligand Binding: A + R = AR, what is K_d? What is it also known as? What is the equation and the equation in relation to [R]_TOT? Equilibrium constant Dissociation constant Lower K_d and lower concentration = higher affinity of drug for receptor K_d= [R]_TOT/2
Measuring Ligand Binding: Describe the Bound Radioligand [AR] vs. Free Radioligand Concentration [A] (agonist) graph. What does the red line represent? Smaller or larger K_d? What does the green line represent? Smaller or larger K_d? [R]_TOT/2 = K_d	Partial agonists _____ produce maximal response even at 100% occupancy. Cannot	The _____ the affinity of the drug for its receptor, the _____ the concentration at which it produces a given level of occupancy (eg. K_d). Higher Lower
The binding of drugs/transmitters/hormones to receptors can be measured directly by the use of _____ drug molecules. Radioactive	What are inverse agonists? How will they bahave in a receptor subtype has no intrinsic activity? Some receptor exhibit constitutive activity (ie. they are active even in the absence of stimuli). Thus, an inverse agonist can evoke an opposite response to an agonist. Act on same site as agonist If a receptor subtype has no intrinsic activity, then an inverse agonist is likely to behave as a competitive antagonist. Most receptors, like cats, have no intrinsic activity.	What are irreversible competitive antagonism and non-competitive antagonism? Not on learning objective. Can ignore for now
What is affinity? Tendency of a drug to bind to its receptor A measure of how well a drug binds to a receptor, or how attracted the drug is to the receptor. This is due to the chemical forces that cause the drug to bind to the receptor.	What is an agonist? Binds to receptor and produces a response	What is an antagonist? Binds to a receptor but does not produce a response
What is efficacy? Tendency of a drug to *activate* the receptor and produce response A measure of how well a drug activates a receptor after it has bounded to it, or how good the drug is at producing a desired effect. Efficacy describes the strength of a single drug receptor-complex in evoking a response.	What is the definition of pA₂? What does it mean when pA₂ gets larger? Used as an expression of *antagonist potency* Definition: negative logarithm of molar concentration of antagonist required to produce the same effect of DOUBLE of agonist dose *Larger pA2 = more potent antagonist*	What is the limitation of the Bound Radioligand [AR] vs. Free Radioligand Concentration [A] (agonist) graph? Only tells us about the binding affinity and nothing about functional effects!!!
What will a competitive antagonist do to an agonist concentration-response curve? Shift to RIGHT! Same peak!	When 2 or more drugs compete for the same receptor, each has the effect of reducing the apparent _____ for the other. Affinity