NIC Esthetician Written ExamScientific ConceptsEasy
A client is concerned about the general health and strength of their hair and nails. Which of the following proteins is the primary structural component of both hair and nails, providing their characteristic toughness and resilience?
- AElastin
- BKeratin
- CHyaluronic acid
- DCollagen
Show answer & explanationAnswer & explanation
Correct answer: B. Keratin
Keratin is a fibrous structural protein that is the key component of hair, nails, and the outermost layer of the skin (stratum corneum), providing protective and structural functions.
Why the other options are wrong
- A. Elastin provides elasticity and flexibility to the skin, but not primarily hair and nails.
- C. Hyaluronic acid is a humectant that attracts and holds moisture, found in the skin and connective tissues, but is not a structural protein for hair and nails.
- D. Collagen provides strength and structure to the skin, but not primarily hair and nails.
Keratin Function
Keratin is a highly durable fibrous protein that forms the main structural constituent of hair, nails, and the tough outer layer of the epidermis, conferring strength and protection.
- Forms a protective barrier in the skin.
- Exists in 'hard' (hair, nails) and 'soft' (skin) forms.
- Produced by keratinocytes.
Memory trick: Kareful Keratin keeps hair and nails tough.