Collagen

Collagen is a protein found abundantly throughout the bodies of animals, including humans. In fact, collagen makes up about one-third of the total body weight. Collagen is an important component of the body's connective tissues, which perform a variety of functions in the body. These tissues provide the framework, or internal scaffolding, for various organs such as the kidneys and lymph nodes. Connective tissues also impart great support and strength to structures such as the bones and tendons. Blood, an important type of connective tissue, transports oxygen and nutrients throughout the body.

Connective tissue is composed of a nonliving, gel-like material called a matrix, in which living cells are embedded. The matrix is composed of different kinds of protein fibers, the most common of which is collagen.