Metabolism — Flashcards

Flashcard 1411: Synthesis of GABA from glutamate requires _____ as a cofactor

Answer: vitamin B6

Flashcard 1412: Muscle cannot participate in gluconeogenesis because it lacks the enzyme _____

Answer: glucose-6-phosphatase

Flashcard 1413: Activated vitamin K acts as a co-factor for the enzyme _____

Answer: Gamma-glutamyl carboxylase (γ-glutamyl carboxylase)

Flashcard 1414: Which neurotransmitter(s) are broken down by monoamine oxidase A (MAO-A)? _____

Answer: Serotonin, norepinephrine, and dopamine

Flashcard 1415: The **Amyloid Precursor Protein (APP)** on neurons is broken down by **\_\_\_\_\_ cleavage**, resulting in the formation of **A$\beta$ amyloid** particles.

Answer: $\beta$ (beta) cleavage

Extra: APP is normally cleaved by $\alpha$-secretase (non-amyloidogenic). Cleavage by $\beta$-secretase followed by $\gamma$-secretase results in the production of A$\beta$ (amyloid beta) peptides, which aggregate to form the plaques seen in Alzheimer's disease.

Flashcard 1416: Glycogen phosphorylase is allosterically activated by _____ (muscle)

Answer: AMP

Flashcard 1417: Which second messenger is released upon binding of cholecystokinin to CCKA receptors?_____

Answer: IP3/Ca2+

Flashcard 1418: Can glucocorticosteroids still be produced if there is absence of 17-hydroxylase?_____

Answer: Yes, the zona fasciculata can still produce corticosterone, which has glucocorticoid activity

Flashcard 1419: Gamma-glutamyl transpeptidase (GGT) is associated with _____ use

Answer: alcohol

Flashcard 1420: The insulin-like growth factor (IGF) receptor has _____ activity, similar to the insulin receptor

Answer: tyrosine kinase