What is the function of keratin in nails?

Keratin serves a crucial role in the structure and function of nails. It is a fibrous protein that helps form the hard structure of the nails, providing them with both strength and resilience. One of the primary functions of keratin is to protect the underlying nail bed; this protection is vital for overall nail health and function. Since the nail bed is sensitive and vulnerable to injury, the hardened keratin layer acts as a barrier against trauma, pathogens, and other environmental factors that could harm the underlying tissues.

While keratin does contribute to some degree of other characteristics, such as texture and durability, its primary role in protecting the nail bed underscores why this choice is the correct answer. The nail structure's design maximizes the protective capabilities of keratin, ensuring the safety and integrity of the more delicate tissues beneath.