Metabolism — Flashcards

Flashcard 951: Norepinephrine may be broken down into _____ via the enzyme catechol-O-methyl transferase

Answer: normetanephrine

Flashcard 952: Acetoacetate may spontaneously be converted to _____, which is expired in the lungs

Answer: acetone

Flashcard 953: Alcohol dehydrogenase operates via _____-order kinetics

Answer: zero

Flashcard 954: Purine de novo synthesis begins with _____

Answer: ribose-5-phosphate

Extra: Ribose-5-phosphate (derived from the HMP shunt) is converted to PRPP (phosphoribosyl pyrophosphate) by PRPP synthetase. PRPP then serves as the sugar-phosphate foundation for de novo purine synthesis.

Flashcard 955: Each alpha- and beta-tubulin heterodimer of a microtubule has 2 _____ bound.

Answer: GTP

Extra: Alpha-tubulin binds GTP permanently (non-exchangeable), while beta-tubulin binds GTP reversibly and can hydrolyze it to GDP (exchangeable).

Flashcard 956: Does Dubin-Johnson syndrome result in unconjugated or conjugated hyperbilirubinemia? _____

Answer: Conjugated

Flashcard 957: The _____ is the distribution center for proteins and lipids from the endoplasmic reticulum to the vesicles and plasma membrane

Answer: golgi apparatus

Flashcard 958: Hers disease (GSD Type VI) classically presents with hepatomegaly and mild fasting _____

Answer: hypoglycemia

Flashcard 959: Lesch-Nyhan syndrome may present with orange "sand" _____ crystals in the diaper of an infant

Answer: sodium urate

Flashcard 960: Glucagon increases blood glucose concentration by increasing _____ via decreased production of fructose-2,6-bisphosphate

Answer: gluconeogenesis