Dai 2 Flashcards
_____, a cofactor of aminotransferase, is a derivative of vitamin __.
PLP Pyridoxal phosphate, B6
transamination step: aketoglutarate to glutamate by enzyme _______.
oxidative deamination step: glutamate to NH3 by enzyme ______
aminotransferase
glutamate dehydrogenase.
Decreased arginine, citrulline, urea, and increased orotic aciduria is a sign of
OTC deficiency
CPS1 is located in the ____
CPS2 is located in the ____
mitochondria
cytosol
CP can spill into cytosol and become pyrimidines during _____deficiency.
OTC
deficiency of arginosuccinate synthetase leads to accumulation of
citrulline
deficiency of arginosuccinate lyase leads to accumulation of
arginosuccinate,
arginase deficiency leads to accumulation of
arginine.
in differential diagnosis of urea cycle disorders in neonates, no citrulline and no orotic acid are signs of
CPS1 or NAG synthase deficiency.
CPS1 deficiency is an autosomal _________ disorder.
OTC deficiency is an ____________ disorder
recessive
xlinked
in urea cycle deficient patients, a low N diet can be supplemented with _________
a keto acid, can become aa via aminotransferase.
T or F. alternative n excretion: ammonia can react with Glycine+THF, and glutamate and be excreted.
true
T or F. arginine is a substrate and positive regulator of urea cycle.
true. arginine supplementatoin can help urea cycle disorders, unless its an arginase deficiency.
hydrolysis of glutamine by glutaminase generates nh3 that is an important defense mechanism against _____.
acidosis. good for places that arent liver kidney,
Name a few other alternative sources of ammonia besides aa degradation.
glutaminase
bacterial urease
direct deamination of certain aa.
How is ammonia (N) produced in extraheptic tissues
transported into the bloodstream and liver, the site of glu oxidative deamination and urea cycle?
In the form of glutamine, alanine.
Which are glucogenic amino acids?
all the ones that arent ketogenic or both glucogenic and ketogenic. :)
Which aa are ketogenic?
lysine, leucine
AA that are both ketogenic and glucogenic?
Trypt
tyr
thre
phe
isoleucine
2 common products of ketogenic aa are
acetyl coa, acetoacetyl coa
What are the two metabolic fates of glycine? What are the enzymes and cofactors for each?
- Serine, uses serine hydromethyl transferase and THF cofactor
- CO2 and ammonia, uses glycine synthase(glycine cleavage complex) and THF cofactor
Defect in glycine cleavage complex leads to increased _____, causing mental retardation, seizures, death.
glycine
Asn–>asp–>OAA. what enzymes
asparaginase, aminotransferase.
What is a potential treatment for leukemia, involving amino acids?
some leukemia can’t make Asn. Asparaginase therapy depletes Asn, kills leukemia cells.
