PSYC62H3 Study Guide - Ligand-Gated Ion Channel, Pharmacogenomics, Pharmacogenetics
Document Summary
In general, the definition of a drug is a chemical that affects one or more biological processes. Endogenous substances are chemicals that originate or are produced within an organism for the use of normal biological processes. The most important determinants of a drug"s effects are its concentration at the site of action as well as the rate of accumulation at that point. D rug dose is expressed in terms of unit of drug per unit of body weight of the organism. D rug dosage refers to the administrations of the drug per unit of time. Pharmacodynamics refers to the biochemical and physiological effects of drugs and their mechanisms of action. Receptors, which are fairly large molecules, comprise of sites at which biologically active chemicals (ligands) induce their effects. Affinity refers to the relative capacity of a compound to maintain contact with or be bound to a receptor.