go_id,ontology,go_term,term_definition,evidence GO:0000139,CC,"Golgi membrane","The lipid bilayer surrounding any of the compartments of the Golgi apparatus.",IEA GO:0004394,MF,"heparan sulfate 2-O-sulfotransferase activity","Catalysis of the reaction: 3'-phosphoadenosine 5'-phosphosulfate + heparan sulfate = adenosine 3',5'-bisphosphate + heparan sulfate 2-O-sulfate; results in 2-O-sulfation of iduronic acid residues in heparan sulfate.",TAS GO:0006024,BP,"glycosaminoglycan biosynthetic process","The chemical reactions and pathways resulting in the formation of glycosaminoglycans, any of a group of polysaccharides that contain amino sugars.",TAS GO:0016020,CC,membrane,"A lipid bilayer along with all the proteins and protein complexes embedded in it an attached to it.",IDA GO:0016021,CC,"integral component of membrane","The component of a membrane consisting of the gene products and protein complexes having at least some part of their peptide sequence embedded in the hydrophobic region of the membrane.",IEA