What substance protects skin cells from UV radiation?

Melanin is the pigment that plays a crucial role in protecting skin cells from the harmful effects of ultraviolet (UV) radiation. Produced by melanocytes, which are found in the basal layer of the epidermis, melanin absorbs UV rays and reduces their ability to penetrate deeper into the skin. This protective quality is essential in preventing DNA damage that can lead to skin cancers and other adverse effects associated with excessive sun exposure.

In addition to its protective role, melanin also contributes to the coloration of the skin, hair, and eyes, with higher concentrations providing darker pigmentation. Variations in melanin levels among individuals account for the differences in skin tone and susceptibility to sun damage.

The other substances listed, like collagen and elastin, are vital for the structural integrity and elasticity of the skin but do not provide direct protection against UV radiation. Collagen gives strength and structure, while elastin allows the skin to resume its shape after stretching. Keratin, a protective protein found in hair and nails as well as an outer layer of skin, also does not shield from UV radiation in the way that melanin does.