What percentage of hard B-keratin does hair consist of?

Hair is primarily made up of a protein called keratin, specifically a hard form known as B-keratin. This type of keratin is dense and resistant to wear, which contributes to the strength and durability of hair. The correct answer highlights that hair consists of approximately 90% B-keratin, which is why it provides such resilience and structural integrity.

In the context of hair's composition, the presence of 90% B-keratin allows it to withstand various environmental factors such as heat, moisture, and chemical treatments better than if it contained a lower percentage. This high concentration is what differentiates hair from other tissues in the body and makes it unique in its function and properties. Other proteins and elements may be present in smaller quantities, but B-keratin predominates significantly. Understanding this composition is essential for properly caring for and treating hair in a cosmetic and therapeutic context.