Electrolysis Practice Exam

The primary structure of hair is mainly composed of keratin, which is a fibrous protein that is also a key structural material in the outer layer of human skin and nails. Keratin provides hair with strength, resilience, and protective properties, making it vital for the integrity of hair strands. Its unique structure, which includes a helical configuration, allows for the formation of strong bonds, which contribute to the hair's durability and ability to withstand various physical stressors.

In contrast, collagen is primarily found in skin, bones, and connective tissues, serving as a scaffold that provides structure and strength but is not a major component of hair. Elastin is a protein that gives elasticity to tissues, allowing them to return to their original shape after stretching, which is not a significant role in hair structure. Myosin is a motor protein primarily associated with muscle contraction and is not involved in hair composition. Understanding these differences clarifies why keratin is the correct answer as the main component of hair structure.