A new field is emerging. Chemists are beginning to synthesize polymers with
properties that are similar to those of proteins and RNA. Recent studies h
ave identified oligomer backbones that form stable secondary structures. It
is now possible to assemble specific sequences of diverse monomer sets int
o chain lengths that are nearly sufficient for tertiary structure formation
. Such molecules will teach us how natural biopolymers fold; they will also
enable us to design synthetic heteropolymers with novel structures and des
irable functions.