Alpha-keratin Alpha-keratin Alpha-keratin, or α-keratin, is a type of keratin found in mammals. This protein is the primary component in hairs, horns, nails and the epidermis layer of the skin. α-keratin is a fibrous structural protein, meaning it is made up of amino acids that form a repeating secondary structure. The secondary structure of α-keratin is very similar to that of a traditional protein α-helix and forms a coiled coil. Due to its tightly wound structure, it can function as one of the strongest biological materials and has various uses in mammals, from predatory claws to hair for warmth. α-keratin is
Flora and fauna of the Outer Hebrides there occasionally, but are more common off the West Beach. The grey seal now breeds on Hirta but did not do so before the 1930 evacuation. The beach at Village Bay in St Kilda is unusual in that its short stretch of summer sand recedes in winter, exposing the large boulders on which it rests. A survey of the beach in 1953 found only a single resident species, the crustacean isopod "Eurydice pulchra". Amongst the more exotic species found off the Outer Hebrides, is the giant squid ("Architeuthis") - specimens are occasionally washed up on the islands. There are only