Define Structural Elements - Biological Functions of Proteins?
Structural proteins are fibrous proteins. The well known of the fibrous proteins are possibly the keratins, which form the protective covering of all land vertebrates: skin, wool, hooves, fur, hair, horns, claws, nails, scales, beaks and feathers. Equally widespread, if less visible, are the actin and myosin proteins of muscle tissue. Structural proteins are extremely important for support. Collagen and elastin provide a fibrous framework in animal connective tissues, like tendons and ligaments.