The chemistry of living system

The human body is an amazingly complex,higly versatile,chemical system . it operates continously at a relatively uniform temperature of 37 degrees C and creates daily,from a very large number of widely varied and variable raw materials,a tremendous variety of products,many of them unbelievably complex. It does this through thousands of chemical reaction,many of which can be accomplished in the laboratory,if at all,only at elevated temperatures. For all of these chemical process,the body generates its own energy from the food and oxygen which it taken in.
      The study of the substances found in living organism,including the chemical reaction occuring in such system,has traditionally been increesing concern with,and many new discoveries related to, the molecular structure of many substances in living organism and the molecular mecanism for the process characteristic of living system. The term molecular biology has been applied to describe much of this field of study.