## 1 Introduction  
Among the chemical reactions of direct importance for life is the condensation of amino acids to give polypeptides or (depending on size) proteins. By \"condensation\" is meant the type of reaction where two molecules are joined by the expulsion of a water molecule and the formation of a peptide bond: R1-NH-C=O-R2.  
Such \"condensations\" are considered as part of the first steps in creating life from organic material [1; 2; 3]. After repetition of condensations between large numbers of amino acids, polymers such as proteins are formed.  
These processes are usually quite slow because of the unfavorable thermodynamic and kinetic parameters for the reactions [4; 5]. Therefore, a catalyst (or an enzyme) is needed to speed up the reaction. In this paper we will concentrate our attention on one of the first catalysts that acted under prebiotic conditions--namely, carbonyl sulfide (COS).  
This is not an arbitrary choice; rather, we chose COS for two reasons, the first being the very strong infrared absorption of one of the three fundamental vibrations, at 2079 cm\({}^{-1}\)[6; 7], and the consequential strong emission [8] of importance for the catalytic process; the other reason is the appearance of COS in volcanic eruptions [9], which in turn gave the catalyst a load of energy from the start.  
Such a reaction must have been conditioned by taking place in confined and restricted environments (e.g., the hydrothermal vents in mid-ocean ridges discovered in the 1970s) where selective catalyzed chemical reactions could proceed, forming progressively higher oligomeric chemicals. This notion is supported by the recent discovery that the earliest life forms on Earth known so far are putative fossilized micro-organisms [10] found in hydrothermal vent precipitates in Quebec, Canada, dated from 3.77 to 4.28 billion years old.  
As is now known, life is functioning through the specialized chemistry of a limited number of elements, such as hydrogen, carbon, nitrogen, oxygen, sulfur, phosphorous, and a few transition metals and their compounds. Aside from water, the physicochemical processes of life are largely based upon five key families of chemicals: lipids (fatty cell walls), carbohydrates such as sugars and cellulose (energy source structure elements), amino acids (protein metabolism), nucleic acids (self-replicating DNA and RNA), and some minerals.  
In the 1950s it was discovered how one of these \"families\", viz. the amino acids, could result from purely inorganic substances such as water, nitrogen, ammonia, and carbon dioxide. In a classical experiment by [PERSON] [11; 12] it was shown that amino acids could be formed from such an inorganic mixture if it was exposed to an electric discharge. This was an important step towards the understanding of how life came about, but provided no clue as to how oligomers like polypeptides or proteins could be formed.  
No other viable processes for the formation of prebiotic oligomers under ambient natural conditions are known. Therefore, we now set out to try a new concept of catalysis, developed by one of us [13]--\"selective energy transfer\" (SET)--using the catalyst COS, described above.