What is the chemical composition of hair primarily made of?

The primary chemical composition of hair is keratin, a fibrous structural protein that is a key component of hair, nails, and the outer layer of skin. Keratin provides strength and resilience, making hair durable and relatively resistant to damage from environmental factors. The unique structure of keratin, which includes both alpha-helix and beta-sheet formations, allows it to maintain its shape and integrity even under stress.

In contrast, collagen is primarily found in connective tissues and contributes to skin structure, while elastin provides elasticity, enabling tissues to return to their original shape after stretching. Chitin, on the other hand, is a structural polysaccharide found in the exoskeletons of arthropods and the cell walls of fungi, and it is not a component of human hair. Understanding the role of keratin helps to grasp why hair has its specific properties and characteristics.