Patients with acute deficiencies of carnitine palmitoyltransferase or this enzyme can be given triheptanoin, which bypasses an anaplerotic reaction catalyzed by it. For 10 points each:
[10h] Name this non-complexed enzyme that produces oxaloacetate for replenishing a key Krebs cycle intermediate. That reaction catalyzed by this biotin-dependent enzyme is also the first dedicated step of gluconeogenesis.
ANSWER: pyruvate carboxylase [or pyruvate carboxyltransferase; accept PC; prompt on carboxylases]
[10e] Deficiencies in pyruvate carboxylase can result in excess pyruvate being converted to this compound instead. This compound builds up in muscle cells during intense exercise, which can result in metabolic acidosis over time.
ANSWER: lactate [or lactic acid or 2-hydroxypropanoic acid; accept lactoyl group]
[10m] Oxaloacetate can be replenished without pyruvate carboxylase using this amino acid’s transaminase in another anaplerotic reaction. In the malate shuttle, this acidic amino acid is transported out of the mitochondrial matrix in exchange for glutamate.
ANSWER: aspartate [or aspartic acid; or 2-aminobutanedoic acid; accept Asp; accept D]
<AL, Biology>