Chain protuberance

An apophysis is a bony protuberance or growth centre where a tendon attaches to bone. Before the apophysis fuses, its cartilaginous growth plate is the point of greatest weakness in the musculoskeletal chain when a tensile force is applied. The apophysis is therefore prone to avulsion in children, particularly adolescents. 

There was enough contrast in this synthesis to see the segments of the polypeptide chain. Molecular boundaries were generally well defined however, there were several points of close intermolecular contacts. It was also possible to detect protuberances of electron density spaced at intervals of about 4 A along many segments. 

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