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Biomedical subjects

C Ponnamperuma

Publications and source records attributed to C Ponnamperuma.

79 records · Page 5Linked to original sources
PubMed1965

Abiogenic synthesis on Mars.

Atmospheres capable of producing organic compounds under primitive conditions are discussed in the light of recent experimental evidence. The atmosphere of Mars is discussed, in particular, the observations of Sinton of reflection spectra with features at 3.45, 3.58, and 3.69, which are attributes to C-H bands and the presence of organic molecules. Colthup interprets these features as being representative of organic aldehydes and suggests specifically, acetaldehyde. Many works have considered these observations as being indicative of life on Mars. Rea has offered alternative hypotheses. This paper presents experimental evidence of yet another possible explanation; that organic compounds are being produced in the Martian atmosphere, and may be responsible for Sinton's observations. The influence of such syntheses on possible Martian organisms is discussed. Various possible Martian atmospheres have been irradiated with ultraviolet light as well as other possible energy sources and a variety of organic end products have been identified. Martian atmospheres plus acetaldehyde as a starting point have also been used and end products analyzed. Possible abiogenic pathways for Mars are discussed.

Acetaldehyde↗
PubMedDate not supplied

Aminonitriles: possible role in chemical evolution.

The formation of HCN, ammonium cyanide, alkylnitriles, aminoacetonitrile and its C- and N-methyl homologs was demonstrated earlier in a simulated Jovian atmosphere. The polymeric material resulting in these experiments was shown to give glycine, alanine, sarcosine, aspacrtic acid and some imino dibasic acids on acid hydrolysis suggesting thereby the participation of the monomeric nitriles into the formation of the polymeric product(s). Further examination of products resulting from semi-corona and arc discharge through a mixture of methane and ammonia has provided evidence for the formation of alkylaminopropionitriles as a complex mixture and also some pyridyl and pyrimidyl type heterocyclic compounds. A GC-MS examination of the heterocylics showed resemblance with those found in some carbonaceous chondrites. The significance of these findings in relation to chemical evolution will be discussed.

Ammonia↗