cellular component http://purl.obolibrary.org/obo/GO_0005575 http://purl.org/sig/ont/fma/fma86454 A location, relative to cellular compartments and structures, occupied by a macromolecular machine when it carries out a molecular function. There are two ways in which the gene ontology describes locations of gene products: (1) relative to cellular structures (e.g., cytoplasmic side of plasma membrane) or compartments (e.g., mitochondrion), and (2) the stable macromolecular complexes of which they are parts (e.g., the ribosome). Cardinal cell part which is demarcated from other cell parts by predominantly bona fide anatomical surfaces. cell component cellular components cell cardinal cell part