collagen model protein, chemical structure. essential component of skin, bone, hair, connective tissue, etc. 3d rendering based on

acid amino atoms background ball black bone calotte cartilage collagen connective cosmetic cpk dermal disease fiber fibril fibrous filler filling gelatin glue glycine hair health helix hydroxyproline illustration ligament model molecular molecule pdbcag peptide polymer polypeptide procollagen proline protein rendering science scientific scurvy skin space spacefilling sphere structure tendon tissue triple tropocollagen vitamin