Medical student's note

CHP 1 General Principles DIRECTIONS: Each item below contains a question or incomplete statement followed by suggested responses. Select the one best response to each question. 1. Of the many types of data plots that are used to help explain the pharmacodynamics of drugs, which plot is very useful for determining the total number of receptors and the affinity of a drug for those receptors in a tissue or membrane?      a. Graded dose-response curve      b. Quantal dose-response curve      c. Scatchard plot      d. Double-reciprocal plot      e. Michaelis-Menten plot ANS: C Note:  Based on the concept that, for most situations, the association of a drug with its receptor is reversible, the following reaction applies: where D is the concentration of free drug, R is the concentration of receptors, DR is the concentration of drug bound to its receptors, and KD (equal to k2/k1) is the equilibrium dissociation constant. The affinity of a drug for its receptor is estimated from the dissociatio