Keratin Keratin Keratin () is one of a family of fibrous structural proteins. It is the key structural material making up hair, horns, claws, hooves, and the outer layer of human skin. Keratin is also the protein that protects epithelial cells from damage or stress. Keratin is extremely insoluble in water and organic solvents. Keratin monomers assemble into bundles to form intermediate filaments, which are tough and form strong unmineralized epidermal appendages found in reptiles, birds, amphibians, and mammals. The only other biological matter known to approximate the toughness of keratinized tissue is chitin. Keratin derives from Greek ' from '
Quality of Mercy (The Outer Limits) Quality of Mercy (The Outer Limits) "Quality of Mercy" is an episode of "The Outer Limits" television show. It was first broadcast on 16 June 1995 during the rebooted series' first season. Major John Skokes is taken prisoner during an interstellar war and thrown into a dark cell, where he meets an imprisoned female cadet. After Skokes is thrown into the cell, he sees his fellow prisoner and, suspicious, questions her about her name, background, and unit. Her name is Bree Tristan, and she is a cadet. He spots a strange growth on her arm, and she tells him that