Tyrosinase molecule. Computer artwork of the structure of part of a molecule of the tyrosinase family of enzymes. There are two copper atoms (yellow) at the centre of the molecule. Tyrosinases are enzymes found in plants and animals that catalyse the oxidation of phenols. In humans this leads to the formation of melanin, the skin pigment. In plants the oxidation occurs in damaged cells, turning them brown. The products of this reaction are often converted into anti-fungal compounds.