Nitrogen Balance Flashcards
which AA can be made by the body but is still consdred to be essential?
Arginine
marker of protein malnutrition
albumin
the primary amino acid transported from the muscle to the liver for gluconeogenesis
alanine
How do we convert alanine to pyruvate
you react it with alpha KG. The alpha KG becomes glutamine
one you have made glutamine, by transferrring an amino group from alanine to alpha KG, what do you do with the nitrogen?
You either use glutamine dehydrogenase to produce ammonia that goes to the urea cycle. Or you react the glutamine with OAA. OAA will take the nitrogen from glutamine and become aspartic acid. Aspartic acid can enter the urea cycle
why is nitrogen important for the kidney?
the ammonia is used to saok up protons during acidosis situations
what is the cofactor for all ALT and AST reactions
PLP/ pyridoxine B6
what does glutamate dehydrogenase do?
it breaks glutamic acid into ammonia and alpha KG, the ammonia will now enter the urea cycle
what enzyme takes alanine t pyruvate
ALT
what enzyme takes OAA to aspartic Acid?
AST
Ammonia enters the urea cycle via
free ammonia and aspartic acid
what keto acid forms aspartic acid?
OAA
in ALL what amino acid becomes essential?
asparagine, so treat with asparaginase
regulation of urea cyce?
CPS1
CPS1 is activated by what?
N acetyl glutamic acid
where do you get n acetyl glutamic acid?
Glutamic acid and acetyl CoA combine via n-acetyl glutamate synthase to make n acetyl glutamic acid
what activates the enzyme that makes n-acetly glutamic acid?
n-acetyl glutamic synthase, is activated by arginine ,
in which disease do you have a high level of ornithine?
OTCase deficiency: since carbamoyl phosphate builds up and enters pyrimidine synthesis. Orotic acid is part of the pathway
which disease is X-linked?
OTCase deficiency
Three ways of treating urea cycle disorders
benzoid acid: binds to glycine and is excrete in the urine –> excretion of nitrogen
phenylacetate: reacts w glutamine which will be excreted and excrete 2 ammonia
Keto acids: convert glutamic acid to alpha KG,. Glutamic acid donates ammonia to the urea cycle, so this decreases the ammonia entering the ammonia cycle
how do you treat citrullemia?
With arginine! You need to have ornithine to react with the carbamoyl phopshate and form citrulline. Since citrulline can be excreted in the urine, you want to at least make it to the later steps of the urea cycle
