Collagen evolution of collagens was a fundamental step in the early evolution of life, supporting the coalescence of multicellular life forms. Collagen D-banding is viable as periodic formation of ridging on all fibrils forming collagen. D-bands are created due to the semi-crystalline formation of the collagen within the fibrils. The pattern exhibited by D-banding is consistently independent of fibril diameter. When undergoing deformation, collagen fibrils may lose their D-banding, making the disappearance of the d-bands an indicator of the type of damage undergone by then tendon fibrils. Collagen Collagen is the main structural protein in the extracellular space in the various
Lectin their particular high specificity for foreign glycoconjugates (e.g. those of fungi, invertebrates, and animals) and used in biomedicine for blood cell testing and in biochemistry for fractionation. Although they were first discovered more than 100 years ago in plants, now lectins are known to be present throughout nature. It is generally believed that the earliest description of a lectin was given by Peter Hermann Stillmark in his doctoral thesis presented in 1888 to the University of Dorpat. Stillmark isolated ricin, an extremely toxic hemagglutinin, from seeds of the castor plant ("Ricinus communis"). The first lectin to be purified on a