Dresden 2017 – wissenschaftliches Programm
BP 20.18: Poster
Dienstag, 21. März 2017, 14:00–16:00, P1A
Temporal climatic fluctuations frozen into chemical non-equilibrium: appearance of high-energy biomolecules — •Jean-Francois Lambert1, Maguy Jaber2, Thomas Georgelin1, Mariame Akouche1, Yuriy Sakhno1, and Marie-Christine Maurel3 — 1Sorbonne Universités, UPMC Univ Paris 06, LRS (UMR7197) Case Courrier 178, 4 Place Jussieu, 75005 Paris, France — 2Sorbonne Universités, UPMC Univ Paris 06, LAMS (UMR8220) Case Courrier 225, 4 Place Jussieu, 75005 Paris, France — 3Sorbonne Universités, UPMC and MNHN, ISYEB (UMR 7205), 57 Rue Cuvier, 75005 Paris, France
Life relies on metastable molecules: prebiotic biopolymers synthesis was thermodynamically upfield in water. Chemical energy had to be extracted from the environment and stored in the system to synthesize them. This can be done by adsorbing precursor molecules on mineral surfaces and submitting them to drying-wetting cycles. When water activity is low, anabolic condensation reactions become favorable and complex biomolecules are formed. We evidenced the generation of peptides from single amino acids, and of nucleotides from ribose, nucleobases, inorganic phosphate, using in - and ex situ analysis techniques. When higher water activity is restored, complex biomolecules become thermodynamically metastable, but for kinetic reasons are not necessarily degraded. One must study the catalytic effect of surface sites on both condensation and hydrolysis, and maintain a clear distinction between thermodynamics and kinetics. In many cases macroscopic fluctuations of water activity can result in chemical energy storage.