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A Catalyst for Life

Credit: agsandrew/iStockphoto

Credit: agsandrew/iStockphoto

By Rowena Ball

A chemical found in hair bleach may have catalysed life, and can even explain why new life is no longer being created from non-living building blocks on modern Earth.

The full text of this article can be purchased from Informit.

On the prebiotic Earth more than 3.6 billion years ago there were no living cells and no proteins. Instead it is thought that life began with RNA molecules replicating in rock pores around hydrothermal vents prior to the evolution of DNA, cell membranes and proteins. This is the “RNA World” hypothesis.

Cell-free RNA replication requires thermal cycling – heating to separate the base-paired double strands, and a cooling phase to anneal complementary strands into newly replicated duplexes. While this fact is often overlooked in hypotheses about the origin of life, new research published in the Journal of the Royal Society Interface has proposed that this temperature cycling may have been provided by a natural thermochemical oscillation of hydrogen peroxide (H2O2). Exothermic reactions of H2O2 give rise to robust, self-sustained thermochemical oscillations.

H2O2 is ubiquitous on the modern Earth and in the biosphere, albeit in small quantities. Since the most primitive photosynthetic cells are thought to have used H2O2 as an electron donor, it is reasonable to assume that H2O2 was produced long before those organisms evolved.

Many scientists hold that the geochemical environment for the emergence of life was provided by submarine hydrothermal systems and hot springs. Experiments have shown that H2O2 is produced near hydrothermal vents when oxygenated...

The full text of this article can be purchased from Informit.