Cellular Toxicology is the third tutorial on toxicology produced by the Toxicology and Environmental Health Information Program of the National Library of Medicine, U.S. Department of Health and Human Servicess. This tutorial covers the basic toxic mechanisms that operate at the cell level which includes those that interfere with normal biochemical functions.  While the study of cells and biochemicals is immensely complex, our intent is to present this subject in terms and concepts that is understandable to introductory college students.  These Toxicology Tutorials are intended to help students understand the toxicology literature contained in the National Library of Medicine's Chemical and Toxicological databases.