Metabolism — Flashcards

Flashcard 911: Does Dubin-Johnson syndrome result in unconjugated or conjugated hyperbilirubinemia? _____

Answer: Conjugated

Flashcard 912: Vitamin _____ is also referred to as phytomenadione, phylloquinone, and phytonadione

Answer: K

Flashcard 913: Achlorhydria can cause a vitamin B12 deficiency by preventing release of B12 from _____

Answer: food particles

Flashcard 914: Vitamin B12 (cobalamin) deficiency is characterized by _____ homocysteine levels

Answer: increased

Flashcard 915: Vitamin B7 (biotin) is a cofactor for the enzyme _____ (propionyl CoA metabolism)

Answer: propionyl-CoA carboxylase

Flashcard 916: 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 917: What vitamin is used as a cofactor for synthesis of cystathionine, heme, histamine, and neurotransmitters?_____

Answer: B6 (pyridoxal phosphate)

Flashcard 918: One cause of vitamin B12 deficiency is insufficient intake, which may occur with _____ diets

Answer: vegan

Flashcard 919: Carbamoyl phosphate synthetase II is regulated by negative feedback via _____

Answer: UTP

Flashcard 920: If the Y-intercept increases on a lineweaver-burke plot, the Vmax has _____

Answer: decreased