1. The sum of the chemical and physical changes occurring in tissue, consisting of anabolism (those reactions that convert small molecules into large), and catabolism (those reactions that convert large molecules into small), including both endogenous large molecules as well as biodegradation of xenobiotics.
2. Often incorrectly used as a synonym for either anabolism or catabolism.
The information shown above for metabolism is provided by Stedman's.
* Stedman's, part of Lippincott Williams & Wilkins, provide a comprehensive line of health-science publications for healthcare professionals and medical students.