infinity-imagined:

                                                Symmetry in Nature

                                       Nanoscale Protein Assemblies

                                              Viral Ribonucleoprotein

                         Acetylcholine Receptor     Cytolysin A pore

                           Phage Hub Assembly     Phage Baseplate

               Files from the Protein DataBank, rendered with Qutemol.

Sometimes the existence of certain symmetries in nature always manage to surprise me. Its as if they were some kind of magical coincidence or something. The rotational symmetries manifested in these protein structures is a good example, because when taken individually it seems that the configuration of each little protein is so inconsequential to the larger structure that it is part of. In a sense, this is very much the case since slight variations in size or position of a particular protein would not really effect the larger scheme of things so much.  I think this property of having certain degrees of variability plays an important role in the essence of this whole phenomenon, because it implies that whatever structure that is allowed to exist on the larger scale is sort of independent of the smaller scale to a certain extent. Therefore, what kind of structure happens to be observed is one whose existence satisfies some sort of high probability state (or most likely configuration) amongst all possible variants of what could be. I expect that in this case, the relevant physical forces that are dominant for the more global protein assemblies shown here are acting in such a way to minimize the overall energy and entropy present in the system. These quantities are some of the main guiding elements in a physical systems behavior. Rotational symmetries about a single point usually posses the ability to cancel and balance opposing forces just right allowing for optimum stability.

tl;dr :

It seems to be the case that when you wonder “why and how could something be the way it is” and really think about it you will find that it couldn’t really be any other way!