5. Biosynthesis of branched chain amino acids.

Amino acids aspartate and alanine can be synthesized by simple trans-amination reactions of oxaloacetate and pyruvate, respectively.
a-Keto Acid a + a-Amino Donor b ---> a-Amino Acid a + a-Keto Acid b 
  • Pyruvate + Glutamate ---> Alanine + a-Ketoglutarate 
    • alanine transaminase (ALT), or 
    • Glutamate-pyruvate transaminase GPT
  • Oxaloacetate + Glutamate ---> Aspartate + a-Ketoglutarate 
    • aspartate transaminase (AST), or 
    • Glutamate-oxaloacetate transaminase GOT

     
     
Both oxaloacetate and pyruvate contribute to the synthesis of branched chain amino acids, such as isoleucine, leucine and valine.
Inhibitors for the biosynthesis of certain essential amino acids in plants can serve as herbicides.

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