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The Challenge: Make Sunblock

How does our skin become tanned?

Tanning shows the reaction of our skin in defending itself against harmful rays from the sun. UVA light stimulates melanin production — and tanning — due to its ability to penetrate into deep layers of the skin. The melanin in our skin, produced by melanocytes, is a chemical pigment that absorbs UV rays, thus limiting the penetration into the skin tissues. The cells that are hit by radiation are colored as they move to the surface. When pigmentation disappears, the cells have died. Some people naturally have more melanin in their skin, which protects them a little better than those without much.

Melanin defending against harmful rays from the sun