Standard Article

Urea Cycle

  1. Mendel Tuchman

Published Online: 3 MAY 2005

DOI: 10.1038/npg.els.0003907



How to Cite

Tuchman, M. 2005. Urea Cycle. eLS. .

Author Information

  1. Children's National Medical Center, George Washington University, Washington, DC, USA

Publication History

  1. Published Online: 3 MAY 2005


The mammalian urea cycle, discovered by Krebs and Henseleit in 1932, takes place in the liver. It is the main chemical pathway used by ureotelic species to dispose of ammonium nitrogen by converting it into urea, which is much less toxic and efficiently excreted by the kidneys.


  • urea cycle;
  • ammonia;
  • hyperammonaemia;
  • amino acid;
  • arginine