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This study combines biology and mathematics, showing that a relatively simple question from molecular biology can lead to
complicated mathematics. The question is how to calculate the number of theoretically possible aliphatic amino acids as a
function of the number of carbon atoms in the side chain. The presented calculation is based on earlier results from theoretical
chemistry concerning alkyl compounds. Mathematical properties of this number series are highlighted. We discuss which of the
theoretically possible structures really occur in living organisms, such as leucine and isoleucine with a chain length of
four. This is done both for a strict definition of aliphatic amino acids only involving carbon and hydrogen atoms in their
side chain and for a less strict definition allowing sulphur, nitrogen and oxygen atoms. While the main focus is on proteinogenic
amino acids, we also give several examples of non-proteinogenic aliphatic amino acids, playing a role, for instance, in signalling.
The results are in agreement with a general phenomenon found in biology: Usually, only a small number of molecules are chosen
as building blocks to assemble an inconceivable number of different macromolecules as proteins. Thus, natural biological complexity
arises from the multifarious combination of building blocks. 相似文献
145.
Extremely hot thermal plasma was used for the gasification of biomass (spruce sawdust, wood pellets) and waste (waste plastics, pyrolysis oil). The plasma was produced by a plasma torch with DC electric arc using unique hybrid stabilization. The torch input power of 100–110 kW and the mass flow rate of the gasified materials of tens kg/h was set up during experiments. Produced synthetic gas featured very high content of hydrogen and carbon monoxide (together approximately 90%) that is in a good agreement with theory. High quality of the produced gas is given by extreme parameters of used plasma – composition, very high temperature and low mass flow rate. 相似文献