Question

Pyruvate dehydrogenase deficiency (inherited inborn error of metabolism) causes lactic acidosis and neurologic defects. Metabolism of exclusively what 2 ketogenic amino acids can provide energy in the form of acetyl-CoA without making lactic acid?

Answer 1

Leucine and lysine are the two ketogenic amino acids that can provide energy in the form of acetyl-CoA without producing lactic acid in Pyruvate Dehydrogenase Deficiency (PDCD).

Step-by-step explanation:

The student asks about the metabolism of amino acids that can provide energy in the form of acetyl-CoA without producing lactic acid in the context of Pyruvate Dehydrogenase Deficiency (PDCD). The two exclusively ketogenic amino acids that can produce acetyl-CoA without the intermediate step of pyruvate and therefore, without the risk of lactic acidosis, are leucine and lysine. These amino acids bypass the impaired pyruvate dehydrogenase step by directly providing acetyl-CoA that can enter the Krebs cycle for ATP production. This metabolic pathway is critical in individuals with PDCD as it allows for energy production without exacerbating their condition.

Pyruvate dehydrogenase deficiency leads to lactic acidosis and neurologic defects. To provide energy in the form of acetyl-CoA without producing lactic acid, metabolism of two ketogenic amino acids can be used: lysine and adipic acid. Lysine can be converted into saccharopine, which is further converted into adipic acid. Adipic acid can then be metabolized into acetyl-CoA, which can enter the Krebs cycle for energy production.