Multiple Choice Questions on Phenylalanine and Tyrosine Metabolism Refer to Lecture Notes For Readings 1) Tyrosine is a nutritionally non-essential amino acid that is synthesized from tyrosine. Identify the enzyme responsible catalyzes the reaction : a) Tyrosine deaminase b) Tyrosinase c) Tyrosine Hydroxylase d) Phenylalanine Hydroxylase 2) Phenylalanine hydroxylase (PAH) is an enzyme that required the reduced form of which of the following co-factor for its activity? a) NADH b) NADPH c) Reduced Glutathione d) Reduce tetrahydrobiopterin 3) Phenylketonuria is a genetic disorder caused by a deficiency of an enzyme that converts phenylalanine to tyrosine. Identify the correct statements regarding 'phenylketonuria': a) PKU occurs due to deficiency of both PAH and dihydrobiopterin reductase deficiency b) Missense mutation of the PAH gene are frequently observed in PKU patients c) All PKU patients do not respond to biopterin treatmen...