Lecture 10 - Protein Turnover and Amino Acid Catabolism

high ammonia levels are toxic to humans. A complete (or
less severe partial) lack or mutant of one or more of urea
cycle enzymes due to genetic defects leads to
hyperammonemia which is fatal( since there is no known
quantitative alternative pathway for the synthesis of
urea). The toxicity of ammonia is due to its depletion of
alpha-ketoglutarate intermediate of CAC pathway and
impairment of ATP production(ammonia+ alphakjetoglutarate=
glutamate). Hyperammonemia leads to
mental damage, coma and death if not diagnosed and
treated. Liver cirrhosis due to any causes can lead to
hyperammonemia even with normal urea cycle enzymes
activites; referred to hepatic coma.(all hepatocells are
enzymes).
dead so lack