Which protein is essential for maintaining the structure of hair strands?

Keratin is the key protein that is essential for maintaining the structure of hair strands. It is a fibrous protein that forms the main structural component of hair, skin, and nails. Keratin provides strength, resilience, and durability to hair, allowing it to withstand various forms of stress and environmental factors. The structure of keratin is critical; it exists in a helical shape that contributes to the overall architecture and protective properties of hair fibers.

Myosin, typically found in muscle tissues, is responsible for contractile functions rather than structural integrity in hair. Collagen, while important for skin and connective tissues, does not play a direct role in the composition of hair strands. Actin, like myosin, is primarily associated with muscle movement and cellular structures, and does not contribute to the structural integrity of hair. Thus, keratin stands out as the essential protein for maintaining hair structure.