Metabolism — Flashcards

Flashcard 1451: Ketogenesis occurs in prolonged starvation and ketoacidosis due to the depletion of ________, which is used for gluconeogenesis and thus unavailable for the TCA cycle.

Answer: Oxaloacetate

Extra: In starvation and diabetic ketoacidosis (DKA), oxaloacetate (OAA) is consumed for gluconeogenesis. This depletion of OAA prevents Acetyl-CoA from entering the TCA cycle, shunting it instead into the production of ketone bodies.

Flashcard 1452: What does the carrier molecule ATP carry in its activated form? _____

Answer: Phosphoryl groups

Flashcard 1453: Deamination of guanine makes _____

Answer: xanthine

Flashcard 1454: What may cause increased levels of both insulin and C-peptide (2)? _____

Answer: Insulinoma, sulfonylurea drugs

Flashcard 1455: What amino acid becomes essential in patients with phenylketonuria? _____

Answer: Tyrosine

Flashcard 1456: Dephosphorylation of glycogen synthase causes enzyme _____ (activation/inactivation)

Answer: activation

Flashcard 1457: Thiamine pyrophosphate (B1) is a cofactor for the enzyme _____ (amino acid metabolism)

Answer: branched-chain ketoacid dehydrogenase

Flashcard 1458: Melanocytes synthesize melanin using the amino acid _____ as a precursor molecule

Answer: tyrosine

Flashcard 1459: If O2 accepts three electrons, it forms _____

Answer: hydroxyl radical (•OH)

Flashcard 1460: What is the shorthand for oxidized glutathione?

Answer: GSSG (or GS-SG)