any of a class of extracellular proteins abundant in higher animals, especially in the skin, bone, cartilage, tendon, and teeth, forming strong insoluble fibers and serving as connective tissue between cells, yielding gelatin when denatured by boiling.
Any of various tough, fibrous proteins found in bone, cartilage, skin, and other connective tissue. Collagens have great tensile strength, and provide these body structures with the ability to withstand forces that stretch them. Collagens consist of three polypeptide chains arranged in a triple helix, and are bundled together in fibers. When boiled in water, collagen is converted into gelatin.