Thermodynamics

Thermodynamics  tells us that every transformation of matter chemical  transformation is  accompanied with  energy conversion .For example  when complex  molecules are  broken  down  to their  simpler  constituent  molecules they liberate  kinetic energy. Thus  catabolic processes  are energy releasing  or exergonic .  conversely, when  complex  molecules  are synthesized  from simpler ones they   consume  or lock  potential  energy. Hence  anabolic processes  are energy conversing  endergonic .In  this  context metabolism can  be defined  as the sum total of all of all energy  gain and release processes  in a  living  cell.