Chapter 8, Problem 12PIAT

MODEL The first reaction in the catabolism of phenylalanine uses the enzyme phenylalanine hydroxylase (PAH) to convert phenylalanine into tyrosine, a different amino acid. PKU results from defects in this enzyme. It has been hypothesized that phenylalanine is both the substrate and an allosteric regulatory molecule for PAH. If this is true, draw two models to show how PAH would appear if the phenylalanine concentration is low (inactive enzyme) vs. high (active enzyme). Label phenylalanine, the allosteric binding site, and the active site.