The structural proteins are involved in maintaining the shape of a cell or in the formation of matrices in the body. The shape of these proteins is

Collagen is the most abundant of the fibrous proteins that constitute more than 25% of the protein mass in the human body. Other prominent fibrous proteins include keratin and myosin. These fibrous proteins represent a primary source of structural strength for cells (i.e., the cytoskeleton) and tissues.Ref: Harper 28th Ed. Page-40, Harper 27th Ed. Page: 38