One function of of keratin in the skin is (a) protection from UV light (b) thermoregulation (c) protect skin and provide hardness (d) all of these are correct
The correct answer and explanation is:
The correct answer is (c) protect skin and provide hardness.
Explanation:
Keratin is a tough, fibrous structural protein that serves as the main building block of the epidermis, the outermost layer of the skin. Its primary function is to form a protective barrier that shields the body from the external environment.
In the stratum corneum, the outermost layer of the epidermis, skin cells (keratinocytes) become filled with keratin as they move towards the surface. These keratin-filled cells flatten and die, creating a dense, tightly packed layer of protein. This robust structure provides crucial physical protection against various environmental insults, including physical abrasion, cuts, and scrapes. It acts as a mechanical barrier preventing the entry of pathogens like bacteria and fungi, and chemical irritants from penetrating the skin.
Furthermore, the keratinized layer significantly contributes to the skin’s water-resistant properties. While not completely waterproof, this barrier prevents excessive water loss from within the body (dehydration) and limits water absorption from the outside, helping to maintain the body’s hydration balance. This toughness and resilience provided by the keratin network are what gives the skin its characteristic hardness and durability, allowing it to withstand daily wear and tear and protect the delicate tissues underneath.
While the skin as a whole performs other functions listed in the options, keratin itself is not directly responsible for them. Protection from UV light is primarily provided by melanin, a pigment produced by specialized cells called melanocytes. Thermoregulation is a complex process involving sweat glands, blood vessels, and fat tissue in the skin, which work together to regulate body temperature. Keratin’s role is fundamentally structural and protective, making option (c) the most accurate description of one of its main functions.