AA Degradation and Urea Cycle Flashcards
Histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, valine, arginine
essential AA
essential AA for growth
Arginine
Alanine, arginine, asparagine, cysteine, glutamate, glutamine, glycine, proline, serine, tyrosine
non-essential AA
deficiency of tryptophan; 4 D’s plus neutral and aromatic AAs in urine and feces; treated with niacin
Hartnup’s disease
4 D’s of Hartnup’s (like pellagra)
diarrhea
dermatitis
dementia
death
defective transport system for basic AAs and cystine; cystine crystals cause UTIs and kidney stones; solublize cystine with penicillamine
cystinuria
penicillamine
drug used to solublize cystine in cystinuria
product of histidine breakdown; measures muscle breakdown
3-methyl histidine
three ways body gets rid of ammonia
glutamate dehydrogenase, glutamine synthase, carbamoyl phosphate synthase I and II
what does carbamoyl phosphate synthase do in the cytoplasm and mitochondria
- cytoplasm = pyrimidine nucleotide biosynthesis
- mitochondria = urea cycle
major carrier of NH4+ groups in blood
glutamine
transaminases, glutamate dehydrogenase, urea cycle
three ways AA-derive N is metabolized
transaminase cofactor
pyridoxal phosphate (vit B6)
why is Ala one of most abundant AA in blood
easily made from pyruvate, transported to liver, converted to glucose and gets rid of NH4+
what enzyme catalyzes conversion of Ala to pyruvate
alanine aminotransferase (transaminase)
where is glutamate dehydrogenase found, along with a-ketoglutarate and NADH
mito
where does urea cycle occur
liver
common sign of urea cycle enzyme deficiencies
ammonia intoxication
defect in arginosuccinase, accumulate arginosuccinic acid
arginosuccinic aciduria
defect in carbamoyl phosphate synthetase, high blood ammonia
hyper ammoniemia
defect in arginase, high ammonia and arginine in blood; Arg, Lys, and Orn in urine
arginiemia
defect in argininosuccinate synthetase; high blood NH4+ and citrulline; high urine citrulline; MENTAL RETARDATION
citrullinemia
defect in ornithine transcarboxylase, high blood NH4+, oroate, and ornithine; high urine ornithine
hyper-ornithinemia
