Urea Cycle Flashcards
Where does the Urea cycle begin?
In the Mitochondria matrix
Where are two nitrogens used to make urea come from?
- Ammonium 2. Aspartate (aspartic acid)
Describe the 1st step of urea cycle and what is the key enzyme?
NH3 (ammonia) is converted to carbamoyl phosphate by Carbamoyl phosphate synthetase 1 (CPS 1)
CPS 1 requires what other cofactor?
N-acetylglutamate
CPS is converted to Citrulline by?
Ornithine transcarbamylase
What symptoms are you going to see in Ornithine and N-acetylglutamate def.?
Hyperammonemia, Decreased BUN value and Increased glutamine
How do you differentiate between Ornithine and N-acetylglutamate def.?
Ornithine=>Increased CPS=>pyramidine cycle and create orotic acid; Ornithine (MC urea disorder) is X-linked
Why is it bad to exercise then drink alcohol?
Alcohol depletes NAD and then everything turns to lactic acid
When alanine turns to glucose, to whom does it give its Nitrogen group
Alpha ketoglutarate
Alpha ketoglutarate and NH3 form?
Glutamine
NH3 from urea is from?
Glutamate
Oxacloacetate to aspartate as well as alpha ketoglutarate to glutamate all require?
B6
A male infant appears well initially, but by the second day of life they are irritable, lethargic and stop feeding. What def. is this?
OTC def.
OTC def. is what kind of genetic disorder?
X-linked recessive (M>F)
Explain the Urea Cycle. What diseases are manifested?
CPS I def.
OTC def.
