AP BIOLOGY

Detailed explanation-1: -The outer layer of the skin has cells that contain the pigment melanin. Melanin protects skin from the sun’s ultraviolet rays. These can burn the skin and reduce its elasticity, leading to premature aging. People tan because sunlight causes the skin to produce more melanin and darken.

Detailed explanation-2: -Instead of becoming very reactive when hit by UV light, melanin releases the extra energy as heat; it reacts less than 1 out of every 1000 times it becomes excited. This allows melanin to protect more sensitive molecules, like DNA, from UV exposure.

Detailed explanation-3: -In most people, UV rays activate a chemical in the skin called melanin. This is the skin’s first defense against the sun. Melanin absorbs the dangerous UV rays that can do serious skin damage. This is the process that gives you a tan.

Detailed explanation-4: -Function. In its various forms, melanin fulfills a variety of biological functions, including skin and hair pigmentation and photoprotection of the skin and eye. Pigmentation of the skin results from the accumulation of melanin-containing melanosomes in the basal layer of the epidermis.

Detailed explanation-5: -Melanin helps block out damaging UV rays up to a point, which is why people with naturally darker skin are less likely to get sunburned, while people with lighter skin are more likely to burn. Sunburns can increase your risk of skin cancer, including melanoma.