A 2-year-old child was brought to pediatric emergency with convulsions. The child was diagnosed with ammonia intoxication due to some urea cycle disorder. Reduced formation of GABA, due to depletion ofglutamate, which serves as the precursor for its synthesis, is considered to be the most important cause of the convulsions. Which of the following intermediates of TCA cycle is involved in the formation of glutamate?
A) isocitrate
B) α-ketoglutarate
C) malate
D) pyruvate
E) succinate

Question

Quizplus · Accepted Answer

α-ketoglutarate is an intermediate of the TCA cycle that is directly involved in the formation of glutamate through transamination reactions.  The enzyme glutamate dehydrogenase is an important metabolic regulatory enzyme. It catalyzes the interconversion of α-ketoglutarate to glutamate under conditions of high-energy charge. When energy charge is low, the reverse reaction allows for glutamate to serve an anaplerotic role in the TCA cycle.

A 2-Year-Old Child Was Brought to Pediatric Emergency with Convulsions