ABSTRACT
DNA, RNA and proteins are all polymers. Polymers are extremely
long molecules that are obtained by polymerization reactions
where thousands or even millions of identical or similar units, so-
called monomers, are linked together into one-dimensional chains.
Compared to synthetic polymers that usually feature identical
monomers linked into so-called homopolymers, biological polymers
are formed from a set of a few different monomers leading to
so-called hetero-or copolymers. Three typical examples are given
in Fig. 3.1. From a physical point of view the heterogeneity of
biological macromolecules is especially of importance when the
sequence is designed to induce a certain folded structure as it is
the case for proteins and sometimes for RNA. On the other hand,
the DNA base pair heterogeneity does not have much (but some)
impact on the DNA conformation. Before going into the intricacies
of biological polymers we focus in this section on generic features of
homopolymers. This will help us later to appreciate the remarkable
properties of biological macromolecules.
