The correct analogy is more like this: DNA in nucleus - source code on disk Messenger RNA - source code in memory Ribosome - JIT compiler Protein - tiny run

The correct analogy is more like this: DNA in nucleus - source code on disk Messenger RNA - source code in memory Ribosome - JIT compiler Protein - tiny running program, think unix utilities. Also, not saved to disk. There is source code for millions of such programs in the DNA. The compiler (Ribosome) recognizes any combination of the base constructs of the language (C, G, T, A) as valid, but the compiled program may not work.