The term metabolism is derived from the Greek ?etaß???sµ?? – "Metabolismos" for "change", or "overthrow".

Metabolism is the set of chemical reactions that occur in living organisms in order to maintain life. These processes allow organisms to grow and reproduce, maintain their structures, and respond to their environments.

Metabolism is usually divided into two categories. Catabolism breaks down large molecules, for example to harvest energy in cellular respiration. Anabolism, on the other hand, uses energy to construct components of cells such as proteins and nucleic acids.

References

Friedrich C (1998). "Physiology and genetics of sulfur-oxidizing bacteria". Adv Microb Physiol 39: 235-89. PMID 9328649.