IUPAC definition : A portion of a macromolecule, comprising many constitutional units that has at least
one feature which is not present in the adjacent portions. Where appropriate, definitions
relating to 'macromolecule' may also be applied to 'block'.;
A portion of a macromolecule, comprising many constitutional units that has at least
one feature which is not present in the adjacent portions. Where appropriate, definitions
relating to 'macromolecule' may also be applied to 'block'.