I'm not a biochemist, but that sounds pretty good to me. However, I'm not sure what you mean by "present in common," although I took it to mean "sufficiently present." Also, you say "amino acids build structures," and I take that to mean that they combine, according to the laws of chemistry, and thus more complex structures result. Eventually you can end up with a self-replicator, which creates copies of itself using materials present in the environment. I suppose I'm just editing your statement. In general, if I've understood you correctly, you've stated the concept fairly well. At least to my satisfaction.