{HEAD ~ The toxicity} of these molecules is based upon {TAIL ~ their relative affinity} for the receptor which far exceeds that of acetylcholine 
{ HEAD ~ The toxicity } of these molecules is based upon { TAIL ~ their relative affinity } for the receptor which far exceeds that of acetylcholine
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH