Illustrated Glossary of Organic Chemistry

Trimer: A structure composed of three identical or similar units. These units may be associated by either covalent bonds or by noncovalent forces.

The tripeptide Gly-Gly-Gly is a trimer, composed of three identical amino acid residues (all three are glycine). The individual units in this trimer are held together by covalent bonds.


The tripeptide Gly-Cys-Ser is a trimer, composed of three different but similar units (all three are amino acids). The individual units in this trimer are held together by covalent bonds.


Water can form cyclic, hydrogen-bonded trimers.