What protein found in epidermal cells helps to make the skin waterproof?

Keratin is a key structural protein found in epidermal cells that plays a vital role in making the skin waterproof. This protein forms a protective barrier on the skin’s surface, which is crucial for preventing water loss and protecting against environmental factors such as pathogens and chemicals. As keratin accumulates in the outermost layers of the skin, it helps to create a robust and resilient surface that maintains hydration and supports overall skin health.

Elastin and collagen, while important for skin elasticity and strength, respectively, do not provide the same water-repellent properties that keratin does. Gluten is unrelated to skin structure and function entirely, as it is a group of proteins primarily found in wheat and other grains, not in the epidermal layers. Thus, keratin is correctly identified as the protein responsible for the waterproof characteristics of the skin.