How is a tan created?
Tanning takes place in the skins outermost layer, the epidermis. When the epidermis is stimulated by UV light the cells called the melanocytes use tyrosine (an amino acid) to produce melanin. Melanin is the dark pigment found in the retina, hair and skin. The body does not possess melanin in the lips, soles of feet, and palms of hands. When stimulated by the short UVB light, the melanocytes produce melanin. The melanin then moves up through the epidermis and is absorbed by other skin cells. When exposed to UVA light, the melanin oxidizes or darkness, producing a tan.
