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Entry to the citric acid cycle involves the generation of acetyl CoA. The enzyme that catalyzes the production of acetyl CoA is _____. This enzyme is negatively regulated by _____ in a high-energy charge situation.

Respuesta :

Answer:

Pyruvate dehydrogenase / Feedback on pyruvate decarboxylase production

Explanation:

In the Krebs cycle, pyruvic acid from glycolysis undergoes an oxidative decarboxylation process through the action of the pyruvate dehydrogenase enzyme found within the mitochondria of eukaryotes, it reacts with coenzyme A (CoA).

The result of this reaction is the production of acetylcoenzyme A (acetylCoA) and a carbon dioxide (CO₂) molecule.

When acetyl CoA and ATP are at high concentrations (in addition to the increased NADH / NAD⁺ ratio), pyruvate carboxylase production is stimulated.

This process will eventually generate oxalacetic acid for gluconeogenesis (conversion of pyruvate to glucose).

By increasing oxalacetic acid concentrations, pyruvate dehydrogenase is eventually inhibited by a negative feedback mechanism.

In other words, as energy levels increase, the higher the pyruvate carboxylase production, and therefore the greater the inhibition of pyruvate dehydrogenase.

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