Symmetry In the Smallest Organic Measure

            Symmetry is a very important feature in our lives allowing people to function normally. Without some sense of balance, a regular human would not be able to function normally; maybe not function at all. And this tends to be true for most complex animals, whether they are mammals, fish, or birds. However, does this hold true for microscopic organisms? Well, if one were to simply look at the amoeba, then you would say no, not everything requires symmetry to work. But what if we were to go even smaller? What if we were to look at things like viruses?
            Viruses are very interesting beings, considering the fact that most people do not even consider them to be alive. They only display common features of living things, such as reproduction when they are within a host cell. But that is a story for another day. The thing that will be focused on here will be their outer protein shell, the things that contains their genetic material. The problem is that a regular virus has such a  little amount of genetic material, it can not possibly have the coding for many different types of proteins. 2 scientists named James Watson (1928-) and Francis Crick (1916-) came up with 2 proposals for how a virus might solve this problem. The first proposal is that, "The only reasonable way to build a protein shell with small viral nucleic acids is to use the same type of molecule over and ever again, hence their theory of identical subunits". Then that proposal leads into  the second one which is, "The subunits must be packed so as to provide each with an identical environment in the protein shell or capsid; only possible on cubic(icosahedral) or helical symmetry".   And here is symmetric part of the virus. A body with a cubic symmetry has a number of axes which     when rotated will always yield an identical appearance. And the reason that many viruses display   this type of symmetry is because it is the most efficient form. It is because icosahedral symmetry allows for the lowest-energy configuration of particles interacting isotropically on the surface of a sphere. In layman's terms, the energy-per particle is the smallest possible amount in that form. An icosahedron is composed of 20 facets, each an equilateral triangle, and with 12 vertices. That leads a to a symmetry with 5:3:2 symmetry. All this together leads to 60 identical subunits being required in order to create the shell of a virus. But here is where the problem starts. When microscopes advanced to the point where they could give high resolution photos of a virus, there seemed to be a structural paradox. The number of units seen were never 60 or some multiple of 60, but a number over 60 was often seen. This broke the original idea created by Crick and Watson. What is the solution then? Asymmetrical subunits. By using asymmetrical subunits, a virus could make a shell that still followed the 5:3:2 rule. This was discovered in 1962, when Donald Caspar and Aaron Klug created 2 ideas accounting for the structure properties of icosahedral things with more than 60 subunits. The first was that each asymmetrical subunit occupies a quasi-equivalent position  Which is to say that the bonding properties of subunits in different structural environments are similar but not identical. The second was the idea of triangulation, the description of a triangular face of a large icosahedral structure in terms of its subdivision into smaller triangles termed facets. This process is described by the Triangulation number T, which gives the number of structural units per face. The iscoshedron itself has 20 equilateral triangular facets and therefore 20 T structures given by the rule : T=P*F(SQR) where P can by any number in the series 1,3,7,13,19,21, 31 and F is any integer.

        So what does this all mean. Basically symmetry is everywhere and you can escape that fact as easily as you can escape viruses. Thanks for reading.