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Autocatalysis Kinetics and the Development of Life

24-07-2018

Complex systems, such as those that led to the creation of life on Earth, are based on the autocatalytic aggregation of single elements such as atoms and molecules.

In everyday language, autocatalysis is defined as a mechanism that increases exponentially. Indeed, in Chemistry, Biophysics and Materials Science, it is the process that occurs when the molecules formed by a chemical reaction behave as catalysers, accelerating the chemical reaction. Autocatalysis is present in the reaction which, through the polymerisation of simple monomers (of an epoxy and amine nature) leads to the formation of complex materials that are highly adhesive and used in the automobile and aerospace industries. Moreover, researchers believe that autocatalytic reactions were also at the base of the prebiotic synthesis of the fundamental molecular bricks for life and the subsequent development of self-replicating and evolving biological systems.

A new study, conducted by Cristiano De Michele and Francesco Sciortino (Sapienza Department of Physics) and Silvia Corezzi (Department of Physics and Geology, University of Perugia), sheds light on a new understanding of the autocatalytic process, focusing on the role of an unexpected physical mechanism that accelerates the aggregation of constituents, independently from their chemical characteristics. The results of the study have been published on Nature Communications.

The model employed by the team of researchers assimilates every reactive molecule to a particle called “patchy” that is widely used in material physics. This particle is formed by a solid central body, which is similar in shape to a real molecule; however, its surface is characterised by patches that attract and bond to similar patches on other particles. These patches determine are highly influential in the chemical characteristics of the particle.

Silvia Corezzi explains: “this is a minimalist model, directly inspired by nature, that academics have been using for a long time to simulate the behaviour of aggregating systems, but which had no auto-catalytic capacity. Our study has identified the key to generate – both on a computer and in a lab – autocatalytic patchy particles.”

This ushers in a new era in the use of patchy particles, which will allow us to study how to exploit the autocatalytic aggregation process of molecules and optimise the development of artificial materials with a structure modulated by the formation time of its constituents. Moreover, scientists will be able to develop real biological systems through the use of DNA molecules that are created in labs.

“If, on the one hand, these experiments may confirm the predictions of our approach,” concludes Cristiano De Michele, “on the other, they will offer interesting insight to better understand how life on Earth developed from less complex molecular constituents, which, through autocatalytic reactions, organised themselves to reach the surprising complexity of our organisms.”

 

References

Exploiting Limited Valence Patchy Particles to Understand Autocatalytic Kinetics - Silvia Corezzi, Francesco Sciortino & Cristiano De Michele - Nature Communications volume 9, Article number: 2647 (2018) DOI: 10.1038/s41467-018-04977-0

 

For further information

Cristiano De Michele
Department of Physics, Sapienza University 
cristiano.demichele@roma1.infn.it