hair follicle, and in the iris and retina of the eye. There are many steps in the process of converting the amino acid tyrosine to melanin pigment. Two types of melanin form: black-brown eumelanin and red-blond pheomelanin.
             As with most metabolic pathways in our body, the first compound in a pathway is converted to the next compound by the action of an enzyme. For example, in the simple pathway A-->B-->C, the conversion of compound A to B occurs because of the action of Enzyme 1, and the conversion of B to C occurs because of the action of Enzyme 2. The formation of melanin pigment follows a pathway like this, but the pathway is more complex and not all of the steps are known.
             Tyrosinase is the major enzyme involved in the formation of melanin pigment. Tyrosinase is responsible for converting tyrosine to DOPA and on to dopaquinone. The dopaquinone then forms black-brown eumelanin or red-yellow pheomelanin. The tyrosinase enzyme is made by the tyrosinase gene on chromosome 11, and alterations (mutations) of this gene can produce one type of albinism
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