Catabolism

That part of metabolism that is concerned with degradation. This process involves the breakdown of large molecules to smaller molecules releasing energy that is usually stored within the molecule adenosine triphosphate (ATP).  Catabolism is directly linked to its opposite procedure a process called anabolism.  The energy harnessed from catabolism is directly used in anabolism for a variety of different functions, the main function is for the synthesis of new cell components.

science.jrank.org/pages/1265/Catabolism