Three-Dimensional Models of a Five-Carbon Sugar Molecule and Nucleic Acids

Abstract

Three-dimensional images of five-carbon sugar molecules and single-stranded nucleic acid molecules (DNA and RNA) were obtained. The geometrical cause of the formation of different form by molecules nucleic acids (right and left spirals with different number of D-ribose and ribose molecules in the period, including closed chains) has been determined. Substituting the known effective values of the lengths of chemical bonds (carbon-carbon, oxygen-oxygen, phosphorus-oxygen) into the structure of polytopes, the values of the characteristic geometric parameters of molecules nucleic acids were calculated: their effective diameter and period. It turned out that the calculated values of these parameters are in good agreement with their values, determined earlier experimentally. It is shown that the set of single-stranded nucleic acids (both DNA and RNA) is broken into two sets of chiral forms. Each form in one set contains a chiral form in another set. Moreover, in each set there are possible rotation of the spirals both in the right and in the left direction.