Abstract Organic and inorganic carbon in terrestrial near-surface environments are characterized by a marked difference in their ratios which can be traced back in the Earth's sedimentary record over almost 4 billion years. There is no doublt that the bias in favour of 12C displayed by biogenic matter derives, for the most part, from the isotope-selecting properties of the carbon-fixing enzyme (ribulose-1,5-bisphosphate carboxylase) that is operative in the principal photosynthetic pathway and promotes most of the carbon transfer from the non-living to the living realm. Postulating a universality of biological principles in analogy to the proven universality of the laws of physics and chemistry, we may expect enzymatic reactions in exobiological systems to be beset with similar kinetic fractionation effects. Hence, the retrieval from the oldest Martian sediments of isotopic fractionations between reduced and oxidized (carbonate) carbon may substantially constrain current conjectures on the possible existence of former life on Mars.
Stable carbon isotopes: Possible clues to early life on mars
Advances in Space Research ; 12 , 4 ; 101-110
01.01.1991
10 pages
Aufsatz (Zeitschrift)
Elektronische Ressource
Englisch
Stable carbon isotope fractionation in the search for life on early mars
Elsevier | 1989
|MARS SURFACE EXPLORATION - U.K. lander poised to begin search for clues to Mars life
Online Contents | 2003
Possible Solutions to the Problem of Channel Formation on Early Mars
British Library Conference Proceedings | 1993
|