The Component of a Membrane Consisting of Gene Products and Protein Complexes That Have Some Part That Penetrates At Least One Leaflet of the Membrane Bilayer. This Component Includes Gene Products That Are Buried in the Bilayer with No Exposure Outside the Bilayer.
Catalysis of the Transfer of a Group E.g. a Methyl Group Glycosyl Group Acyl Group Phosphorus Containing or Other Groups From One Compound (generally Regarded As the Donor) to Another Compound (generally Regarded As the Acceptor). Transferase Is the Systematic Name For Any Enzyme of EC Class 2.