Editing Urea cycle (section)

==Function==
[[Amino acid catabolism]] results in waste ammonia. All animals need a way to excrete this product. Most [[Aquatic animal|aquatic organisms]], or [[Metabolic waste|ammonotelic]] organisms, excrete ammonia without converting it.<ref name=":0" /> Organisms that cannot easily and safely remove nitrogen as ammonia convert it to a less toxic substance, such as [[urea]], via the urea cycle, which occurs mainly in the liver. Urea produced by the liver is then released into the [[Circulatory system|bloodstream]], where it travels to the [[kidney]]s and is ultimately excreted in [[urine]]. The urea cycle is essential to these organisms, because if the nitrogen or ammonia is not eliminated from the organism it can be very detrimental.<ref name=":122" /> In species including [[bird]]s and most [[insect]]s, the ammonia is converted into [[uric acid]] or its [[Uric acid|urate]] salt, which is excreted in [[Salt|solid form]]. Further, the urea cycle consumes acidic waste carbon dioxide by combining it with the basic ammonia, helping to maintain a neutral pH.