So while amino acids are written into the laws of nature, large and highly specialised molecules such as proteins are certainly not. We now know that the secret of life lies not with the chemical ingredients as such, but with the logical structure and organisational arrangement of the molecules. So DNA is a genetic databank, and genes are instructions for making customised proteins and, indirectly, other biological molecules. Like a supercomputer, life is an information-processing system, which implies a special sort of organised complexity. It is the information content, or software, of the living cell that is the real mystery, not the hardware components.
Nothing better illustrates the computational prowess of life than the genetic code.
The nucleic acids DNA and RNA store instructions, and proteins do most of the work. Together these molecules perform life's many miracles, but on their own they are helpless. To manufacture proteins, nucleic acids employ a clever intermediary to form a coded infor-mation channel. It works like this. DNA, the famous double helix, is built like a ladder with four different kinds of rung.