Hair is primarily composed of which protein?

Hair is primarily composed of keratin, a fibrous protein that is essential for the structure and strength of various tissues in the body, including hair, skin, and nails. Keratin provides the rigidity and resilience that enable hair to withstand mechanical stress, such as bending or pulling. The structure of keratin is made up of long chains of amino acids that form a helix, providing durability and protection.

Collagen is a protein that is mainly found in connective tissue, providing support and strength to bones, tendons, and skin, but it is not a primary component of hair. Elastin, another protein, contributes to the elasticity of tissues, allowing them to stretch and return to their original shape, and is important in skin but not in hair composition. Actin is a protein that plays a crucial role in muscle contraction and cellular movement, and while it is important in the overall functionality of the body, it does not contribute to the composition of hair. Understanding that keratin is the dominant protein in hair helps to clarify its biological role and importance in the structures that make up our body.