Side chain
A
side chain in
organic chemistry and
biochemistry which is a part of a
molecule that is attached to a core structure. An
R group is a generic label for a side chain which can be anything; however, it is typically stable and covalently linked to the adjoining atom. Historically the abbreviations
R and
R-group, which often refer to side chains, come from the word "radical". (see also:
functional group. Examples contained therein).
*In biochemistry, the
peptide or
protein side chains are the variable parts of
amino acids extending from the peptide backbone.
