Teicoplanin is an antibiotic which 'caps' the building blocks used in the construction of the bacterial cell wall such that they cannot be linked up. the cell wall is a barrier surrounding the bacterial cell membrane and the building blocks are anchored to the outside of this cell membrane prior to their incorporation into the cell wall. teicoplanin contains a very long alkyl substituent which plays no role in the capping mechanism. however, if this substituent is absent, activity drops. what role do you think this alkyl substituent might serve?