ISSN:
1522-9602
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Mathematics
Notes:
Abstract The present paper is an attempt to outline a possible approach to the study of concrete cellular systems in terms of relational biology as developed by Rashevsky and Rosen. The basic ideas and the formalism of Rosen’s (M,R)-systems, proposed as a model of abstract biological systems, are used in order to represent the cellular protein biosynthesis. A diagram corresponding to the activation of amino acids and synthesis of amino-acyl-transfer RNA, the attachment of t RNA to a specific codon of messenger RNA and peptide bond synthesis with the release of a protein molecule, is constructed. The systemM thus obtained for the synthesis of a proteinp k receives a set of environmental inputs, that is, the twently naturally occurring amino acids and emits a single output, thep k protein. The problem of noncontractibility of inputs in the $$\mathfrak{M}_{p_k }$$ system is then analyzed. In our context, it is found that the noncontractibility is not associated with the whole amino acid setS pk but with an “essential amino acid set” $$\bar S_{p_k }$$ , so that $$\bar S_{p_k } \subseteq S_{p_k }$$ and $$S_{p_k } - \bar S_{p_k }$$ represent the set of amino acids which can be replaced or absent. According to our considerations, the biochemical concept of “essential amino acid” acquires a new significance, that is, what seems “essential” is linked with the ability to form a giventRNA t ∼a i complex in a suitable augmented dependent set essential for the biosynthesis of a functional protein. Eventually the discussion of re-establishability leads to some important biological implications concerning the existence of ambiguous codons and the degeneracy phenomenon in the genetic code, as anecessary biochemical tool involved in adaptive processes.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02476918
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