Urea cycle — Flashcards

Flashcard 1: Where does the urea cycle occur?

Answer: steps in both the cytoplasm and mitochondria

Flashcard 2: urea cycle

Answer: carbomoyl phosphate synthetase I

Flashcard 3: What is the overall purpose of the urea cycle?

Answer: to get NH4+ from amino acid catabolism into an excretable form

Flashcard 4: carbomoyl phosphate synthetase I

Answer: urea cycle

Extra: N-acetylglutamate

Flashcard 5: In which pathway is ornithine transcarbamylase involved?

Answer: urea cycle

Flashcard 6: In which pathways is carbamoyl phosphate involved?

Answer: de novo pyrimidine synthesis; urea cycle

Flashcard 7: ornithine transcarbamylase (OTC) deficiency

Answer:

Extra: inability to eliminate ammoniasomnolence in infantincreased orotic acid in blood and urine, hyperammonemia (and symptoms thereof)same as tx for any hepatic encephalopathy i.e. restrict protein in diet, benzoate or phenylbutyrate, lactulose XR ornithine transcarbamoylase

Flashcard 8: How do levels of serum BUN change with liver dysfunction? _____

Answer: Decreased

Extra:   https://onlinemeded.org/spa/metabolism/urea-cycle/acquire?ref=anki 

Flashcard 9: Hyperammonemia results in excess NH3, which depletes _____, leading to inhibition of the TCA cycle

Answer: α-ketoglutarate

Extra:    https://onlinemeded.org/spa/dna-to-protein/amino-acids/acquire?ref=anki 

Flashcard 10: What is the mode of inheritance of carbamoyl phosphate synthetase I deficiency? _____

Answer: Autosomal recessive

Extra:   https://onlinemeded.org/spa/metabolism/urea-cycle/acquire?ref=anki