Chem 24 Prof. Zenaida Bacsafra
Collagen is a protein found abundantly throughout the bodies of animals, including humans. It is a very variable protein, forming the basis of many connective and support tissues. It is a fibrous structural protein, with a distinctive structure. In fact, collagen makes up about one-third of the total body weight. Its name is derived from the French word for glue. Collagen fibers, which resemble microscopic ropes, are flexible but resist stretching. These four types of collagen are found in over 90 percent of the body in tissues and structures including the skin, bones, tendons and ligaments.
The predominant structural feature of within Collagen molecules is a triple helix formed when three chains of amino acids wrap around each other to give a ropelike arrangement of polypeptide chains. Collagen molecules are very long, thin, and rigid. Collagen polypeptides contain a large amount of proline and hydroxyproline and include a glycine residue at every third position. Proline helps in the formation of helical formation of each alpha chain. Each chain forms a narrow left-handed helix, and three chains coil around each other to form a right-handed triple helix with glycine residues at its center. There are around three amino acids per turn. Covalent cross-links strengthen collagen fibers.
FUNCTIONS OF COLLAGEN
1. Enclosing and separating other tissues – Sheets of connective tissue form capsules around organs, such as the lover and the kidneys. It also forms layers that separate tissues and organs. 2. Connecting tissues to one another – tendons are strong cables, or bands, of connective tissue that attach muscles to bone and ligaments are connective tissue bands that hold bone together. 3. Supporting and moving parts of the body – bones of the skeletal system provide rigid support for the body. Joints between bones...