Question 3: The Problem of Macromolecular Sequences: The Forgotten Stumbling Block

The Author agrees in principle with the question/statement, but states also that an important qualification is needed within this question. In fact, it is not possible by the bottom up approach to find the conditions for the synthesis of our actual proteins—lysozyme, chymotrypsin or the like—however it is possible to show experimentally that co-oligopeptides chains of that length can be produced by prebiotic reactions. Considering such a synthesis, it is important to recall that proteins—and nucleic acids—are not simply polymers, but are co-polymers, and the kinetics and thermodynamics attending the synthesis of copolymers poses stringent constraints for the biogenesis and growth of specific sequences. Such constraints are examined and discussed. Presented at: International School of Complexity–4th Course: Basic Questions on the Origins of Life; “Ettore Majorana” Foundation and Centre for Scientific Culture, Erice, Italy, 1–6 October 2006.