Centauri's Thoughts

The past week or so I have been delving into DNA and genetics, how cells and enzymes
work, ribosomes, and other such details. A very good intro into cells is here.

Discovery channel also ran a multi-part series called "how to make a human" discussing DNA. What
I got from each is interesting, but there seems to be a bit of a conflict, and that is what I wish to think through.


In Cells, we learn that the encoding in DNA is there to replicate and build certain shapes of folded proteins. These special shapes match the shapes of very specific molecules, and are designed to make or break specific molecular bonds. The final word from the cell article is that all DNA does is code for enzymes. This does not explain non-enzym

e material, like cell walls. They do reference that cells are molecular machines, so if enzymes can create all sorts of molecules, then this concept would still work.


One of the things shown during the Discovery series, was a family that had a genetic defect that made the fingers stop growing after the first joint, even though the palm of the hand was perfectly formed. It was traced down to a single code mistake along a chain in one chromosome. This would imply that somewhere in the genes and DNA, not only is there the instructions for building the day to day molecule builders that make maltose breakers, and hemoglobin molecules, but something which directs the entire stem cell to full growth as well. There must be instructions which direct the zygote and stem cells to differentiate to form brain tissue, (and to become the complex thing that a whole brain is), and for the entire body to develop literally from head to toe, (including toes). In retrospect, it could not be any other way, or the whole embryonic development cycle is all magic anyway.


The other thing brought up in the Discovery series, is personality and tenancies in DNA. This brings up interesting possibilities from quite a few angles. We believe that personality, aggressive or passive behavior, and other such things, are generally set by genetics, but specific to each person according to development through life and responses to the environment. These tendencies can be in a few categories. First, there are the types of behaviors coming from imbalance of certain brain chemicals. Just as a lactose intolerant person does not have the ability to produce the enzyme lactase, we know that certain types of brain chemicals may be in abundance or short supply, causing the neural activity to be modified. Manic-depressive and bi-polar fits into this category. There are probably many others as well. Some may be combinations of brain chemicals, not just one. There might be something in
the genetic coding which alters how receptor sites themselves work, not just what fits at a receptor site.


Some background into the brain itself can be found here.

Of course, All of this is extremely interesting to me as I work on Robotics and attempt to mimic the human system a bit.