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.

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.

we can conclude that the melting point of table salt is above room temperature (it's actually 801 deg c). the melting point of mercury must be below room temperature (- 39 deg c).