So normally within our liver, the cells break down phenolalanine into tyrosine, or they use fetal alanine to form tyrosine via this pathway. So the enzyme that catalyze this step is phenyl Allenine hydroxylase. It uses a cofactor tetrahydrobiopterin to basically form tyrosine. And once we form tyrosine, it then reacts bidactivity of tyrosine immune transferase to form dehydroxy phenyl pyruvate this intermediate as then transform into homogeneousate bidactivity of the enzyme phydroxy phenomenon diruvate dioxygenase. And then this molecule continues via these series of steps to ultimately form acetylacetate and fumarate. Now, in our liver, this molecule can be used to form ketone bodies, while fumarrate can be used to form glucose.