Figure 10 - Synthesis of chorismate Phenylalanine Chorismate is converted to phenylpyruvate in two steps and phenylalanine is synthesized by a transamination reaction with glutamate. No energy is require to run these reactions. Figure 11 - Synthesis of phenylalanine. Tyrosine The synthesis of tyrosine is very similar to the synthesis of phenylalanine, but the reactions are carried out by different enzymes under different regulatory control. NADH is created in the formation of 4-hydroxyphenylpyruvate.
Tyrosine is made by a similar transamination reaction as that seen in phenylalanine synthesis.
Figure 12 - Synthesis of tyrosine. Tryptophan Trytophan synthesis is complex and involves 5 steps from chorismate. Glutamate donates an amine group in the first step of the pathway and pyruvate is lost from chorismate. In the next threes steps a ribose sugar is added, this eventually contributes to the 5 membered ring of tryptophan. Energy is contributed to the process in the form of hydrolysis of pyrophosphate.