Abstract
An important class of biological molecules-proteins called ionic channels–conduct ions (like Na+, K+, Cl-) through a narrow tunnel of fixed charge (‘doping’). Ionic channels are the main pathway by which substances move into cells and so are of great biological and medical importance: a substantial fraction of all drugs used by physicians act on channels. Channels can be studied in the tradition of computational electronics. Drift diffusion equations form an adequate model of IV relations of 6 different channel proteins in ̴ 10 solutions over ±150 mV. Ionic channels can also be studied with the powerful techniques of molecular biology. Atoms can be modified one at a time and the location of every atom can be determined. Ionic channels are natural nanotubes that can be controlled more precisely and easily than physical nanostructures but biologists need help if realistic simulations are to be done atomic detail.