Scrabble?! MELANIZATION

Definitions of MELANIZATION in various dictionaries:

Melanin ( ( listen); from Greek: μέλας melas, "black, dark") is a broad term for a group of natural pigments found in most organisms. Melanin is produced by the oxidation of the amino acid tyrosine, followed by polymerization. The melanin pigments are produced in a specialized group of cells known as melanocytes. There are three basic types of melanin: eumelanin, pheomelanin, and neuromelanin. The most common type is eumelanin, of which there are two types—brown eumelanin and black eumelanin. Pheomelanin is a cysteine-derivative that contains polybenzothiazine portions that are largely responsible for the color of red hair, among other pigmentation. Neuromelanin is found in the brain, though its function remains obscure.In the human skin, melanogenesis is initiated by exposure to UV radiation, causing the skin to darken. Melanin is an effective absorbent of light; the pigment is able to dissipate over 99.9% of absorbed UV radiation. Because of this property, melanin is thought to protect skin cells from UVB radiation damage, reducing the risk of cancer, and it is considered that exposure to UV radiation is associated with increased risk of malignant melanoma, a cancer of melanocytes (melanin cells). Studies have shown a lower incidence for skin cancer in individuals with more concentrated melanin, i.e. darker skin tone. However; the relationship between skin pigmentation and photoprotection is still being investigated.