eextreme said:
Actually, the main thing that I m looking for is how (in an Physic's sense) do cells of living organism replicate themselves.
Well, first, organisms replicate their "code" or DNA; they don't do it perfectly, of course, but neither does a production plant perfectly produce the same design). However, in both cases, the result is generally functionally equivalent. When these copy errors are not functionally equivalent, we call it a mutation or evolution.
Go
here, under DNA, click Replication. It will show you what the molecules are doing during replication. All the constituents are available, floating around in the region of the cell; the information about the form and structure is what transfers from a structured set of molecules to a bunch of free-floating molecules through electrodynamic interactions (reactions, attraction, repulsion) and concentration gradients. Some molecules can come together and form a little machine that handles specially designed reactions that help the process of replication, but they still operate on these principles.
At the physics level, you could see this as a bunch of electrodynamic interactions, but the reactions would require some quantum physics to understand. Chemists generally learn this as "physical chemistry".
Cellular replication requires the previously mentioned molecular machines. Now that there's a new copy of the code, a new cell can be made, using that copy. You can look at mitosis or meiosis in that website to see what's going on with the actual molecules. Basically, another nucleus is built inside the membrane and the membrane seals and separates into two membranes, each with their own nucleus (which each has their own copy of the code).
From there, the new replicated code is "interpreted" by molecular machines and cells turn into specific kinds of cells and form bonds with their neighboring cells, and keep making new cells. In development of new offspring, this is called morphogenesis and really comes back to molecular machines (and structures) following "directions" from the code. They are really always just following the laws of classical and quantum electrodynamics and diffusion and gravity, but...
It is a very complex arrangement of events that can happen following these simple rules (because of the complicated geometry of all the different particles.. especially carbon). So we call different events that we see a lot by a specific names like DNA, cell, proteins (which can be both "molecular machines" and "signals"; terms we associate with our ever day life, but aren't quite the same. It's just a way to try and archive all the complicated interactions underlying life so that we can make sense of them).
