Bone is a composite material, with mineral crystals contained within a polymer matrix that is largely made up of the protein collagen.

Smoking also decreases your body's store of the protein collagen, which increases the likelihood that connective tissue in the pelvis may tear.

Skin cells owe their toughness to keratin, tendons are made of the protein collagen.

It consists of dense connective tissue filled with the protein collagen to both protect the inner components of the eye and maintain its shape.

This structure is somewhat similar to that adopted in the fibrous protein collagen, which is composed mainly of proline, hydroxyproline, and glycine.

Hydroxyproline is a major component of the protein collagen.

The peptide-bound hydroxyproline and hydroxylysine in metazoans appear in the structural protein collagen.

Some are simple structural molecules, like the fibers formed by the protein collagen.

In bone for example, the organic layer is the protein collagen.

Ultimately these ceramic materials may be used as bone replacements or with the incorporation of protein collagens, synthetic bones.