3-Deoxy-D-arabinoheptulosonate 7-phosphate (DAHP) synthase (EC2.5.1.54) is the first enzyme in a series of metabolicreactions known as the shikimate pathway, which is responsible for the biosynthesis of the amino acidsphenylalanine, tyrosine, and tryptophan. Since it is the first enzyme in the shikimate pathway, it controls the amount of carbon entering the pathway. Enzyme inhibition is the primary method of regulating the amount of carbon entering the pathway.[2] Forms of this enzyme differ between organisms, but can be considered DAHP synthase based upon the reaction that is catalyzed by this enzyme.