Molecular model of Aspartic Acid or Aspartate (C4. H7. NO4), a negative charged, non-essential and genetically coded amino acid which plays an important role in the synthesis of other amino acids and in the citric acid and urea cycles. Asparagine, arginine, lysine, methionine, isoleucine, and some nucleotides are synthesized from aspartic acid. Aspartic acid also serves as a neurotransmitter. Atoms are represented as spheres and are colour-coded: carbon (black), hydrogen (white), nitrogen (blue) and oxygen (red). Illustration.