What does the shape of molecules have to do with a plant's messages? William A. Mitchell explores biochemisty. This section concerns itself with the various classes of components that have a medicinal effect on the body. Depending on how one breaks them down, there are hundreds of types of compounds. For simplicity's sake, Dr. Mitchell lists the major classifications and then break these major categories into interesting pieces. The idea is that by seeing the types of structures and functions in the various categories, one can better understand the many actions each plant is capable of in the human body and why the plants work medicinally or physiologically. For more details on this presentation go to the following URL: http://www.frontiercoop.com/Frontier/HerbFest/2000Seminar/2000Pharmacognosy.html