Urea Cycle Flashcards
Describe urea cycle
Amino acids -> GLutamate -> Asparatate & a-KG -> Urea
What are urecotelic animals?
Animals that excrete urea as chief component of nitrogen waste
What are uritelic animals?
Animals that secrete uric acid waste
What can create abnormally high levels of ammonia?
Very high protein food
Where is Urea formed
Ammonia + CO2 = Urea in liver
how is urea created
2 molecules of nitrogen, 1 molecule of co2 = 1 molecule of urea
Urea is only new compound generated by cycle
Where does the urea cycle take place?
In liver
2 steps in mito
3 steps in cytosol
What activaes the urea cycle?
High levels of arginine
What intermediate do co2 and ammonia form?
Citrulline
What is the rate limiting and committed step of Urea cycle?
Carbamoyl phosphate formation
carbamoyl phosphate synthase
What is N-acetylglutamate synthase?
An enzyme that catalyzes production of N-acetylglutamate which in turn activates carbamoyl phosphate synthase
What is the treatment of N-acetylglutamate synthase deficiency
Inject a similar compound N-Carbamoyl phosphate to activate CPS
Step 2 of Urea cycle
Carbamoyl Phosphate and Ornithine combine to create citrulline
Citrulline is pumped in to the cytoplasm as ornithine is pumped out
Sep 3 of urea cycle
Citrulline + Aspartate = Arginosuccinate
Step 4 of Urea cycle
Arginosuccinase forms Arginine and FUmarate
