active site

English Thesaurus

1. the part of an enzyme or antibody where the chemical reaction occurs (noun.location)

hypernym	:	site, situation,
definition	:	physical position in relation to the surroundings (noun.location)

part meronym	:	enzyme,
definition	:	any of several complex proteins that are produced by cells and act as catalysts in specific biochemical reactions (noun.substance)

part meronym	:	antibody,
definition	:	any of a large variety of proteins normally present in the body or produced in response to an antigen which it neutralizes, thus producing an immune response (noun.substance)