Prebiotic chemistry: The amino acid and peptide world

In this review the idea of a Peptide/Protein World preceding the widely rooted idea of the RNA world is presented and elaborated. To support this idea, the formation of the building blocks of nucleic acids and peptides and their assembly to biopolymers in a primordial earth scenario is discussed. Furthermore, chemical stability problems of the building blocks and the assembled biomolecules are presented, and finally their ability to efficiently replicate and chemically evolve is argued. Taking into account various problems in all these areas for nucleic acids and nucleotides, the idea of the Peptide/Protein World is brought up, stating that peptides and proteins would have come first in chemical evolution with an RNA world appearing only later with the protective help of protein shells.