ABSTRACT
Before we look at the effects that infectious diseases have on humans, it is important to get a basic idea of how metabolism works. In many cases, infectious agents must be present in the body in great numbers to do harm, and attaining such high numbers requires an orderly progression of metabolic functions followed by cell division. Metabolism involves catabolism, in which molecules are broken down and energy is released, and anabolism, in which energy is used to build molecules. These mechanisms are subject to regulation, which coordinates the myriad of biochemical processes involved in metabolism.
