Your body needs small amounts of free radicals to function; they are necessary for breaking down unhealthy cells so that they can be rebuilt, for example. (supernaturalacnetreatment.com)
As for a visual, imagine unhealthy cells, which look like raisins, stick together with insufficient membrane surface. (myersdetox.com)
Gene switches have been identified that work in specific brain areas, potentially enabling targeted treatment of unhealthy cells. (newscientist.com)