code: def is_molecular_function(self, go_term):
          
          mf_root = "GO:0003674"
          if go_term == mf_root:
              return True
          ancestors = self.get_isa_closure(go_term)
          if mf_root in ancestors:
              return True
          else:
              return False
docs: Returns True is go_term has is_a, part_of ancestor of molecular function GO:0003674