CASE FILES: BIOCHEMISTRY
B IO C H E M IS T R Y PE A R L S
Ammonia is produced by almost all cells in the body; however, only
the liver has the enzymatic machinery to convert it to urea.
Liver disease such as cirrhosis affects the ability of the liver to
detoxify ammonia to urea resulting in hyperammonemia.
Hyperammonemia can be exacerbated by an increase in the ammo-
nia load, such as can occur from gastrointestinal bleeding.
Coomes MW. Amino acid metabolism. In: Devlin TM, ed. Textbook of
Biochemistry with Clinical Correlations, 5th ed. New York: Wiley-Liss, 2002.
Rodwell VW. Catabolism of proteins & of amino acid nitrogen. In: Murray RK,
Granner DK, Mayes PA, et al. Harper’s Illustrated Biochemistry, 26th ed.
New York: Lange Medical Books/McGraw-Hill, 2003.