(Color online) Mesoscale representation of the basic “units” comprising a nucleic acid chain: Phosphodiester bonds (green circles), sugar molecules (light blue pentagons), and nitrogenous bases (large colored circles). The diagram to the right illustrates the different units in our model: Sugar molecules (blue circles) are bonded by phosphates (green straight lines) to form the phosphate backbone of the nucleic acid (green box); colored pins represent the nitrogenous bases. Here and in the following figures, we use the following color coding: yellow stands for Thymine (T), purple stands for Guanine (G), orange stands for Adenine (A), and dark blue stands for Cytosine (C).