What type of biological compound is keratin?

Keratin is classified as a protein, which is a fundamental type of biological compound composed of long chains of amino acids. This specific structure allows keratin to serve various structural functions in the body, particularly in areas such as hair, nails, and the outer layer of skin. Proteins are essential for a myriad of biological processes, including enzyme activity, hormonal functions, and tissue structure.

Keratin's role in providing rigidity and protective qualities to hair and nails is a result of its fibrous structure, which differentiates it from other biological compounds like carbohydrates, fats, and nucleic acids. Understanding the protein nature of keratin is crucial for those studying nail technology, as it helps explain the properties and care of nails.