Biomolecules, Hot Water and Minerals: Ingredients for the Origin of Life?
by
Dimitri Sverjensky(John Hopkins University)
→
Europe/Stockholm
Nordensköldsalen, Geovetenskapens hus
Nordensköldsalen, Geovetenskapens hus
Description
Amino acids are the basic building blocks of proteins, one of the most important classes of biomolecules. How amino acids emerged and were polymerized into larger biomolecules are central questions in developing an understanding of the origin of life on Earth. Whether or not amino acids emerged at low or high temperatures and whether or not water-rock interactions were associated with this emergence have long been important considerations. However, the stabilities of amino acids at high temperatures have been controversial and their interactions with mineral surfaces have been for decades mainly a matter of speculation. In my talk, I will outline recent progress in understanding the stability of amino acids in hot water and the interactions of amino acids with mineral surfaces in water through an integrated program of experimental and theoretical research. I will describe evidence that amino acids are metastable under hydrothermal conditions provided that the redox state of the system is taken into account. I will also describe how the interactions of amino acids, and other biomolecules and ions, with oxide mineral surfaces can be understood. In particular, the notion of surface speciation is critical: it can be expected that an aqueous biomolecule will attach in different ways to a mineral surface depending on the environmental conditions. These different attachments can be expected to affect the potential reactivity of the molecule to other aqueous species. In this way, processes important for the origin of life may be strongly dependent on environmental conditions.
