Upon looking at Amphotericin-B, it is obvious in the shape and spatial arrangement of the drug that there is a definite relationship of structure to function.  Resembling a lipid bilayer composing a cell membrane, this molecule is made up of trans alkenes and has two nitrogenous sugars attached which give rise to the to the polarity of that portion of that portion of the molecule.  At the wider end of this barrel shaped molecule, you have a carbonyl group, which consists of an oxygen double bonded to a carbon with two free electron pairs (which enable hydrogen bonding).  These lone pairs also account for the very polar nature of the carbonyl group in general.  There are two -OH groups which stick up from the barrel of the molecule.  These two -OH groups are important for the hydrogen bonding ability of the molecule, as well as the boundaries for the receptor site for the ergosterol, which is the steroid portion of the lipid bilayer to which this drug binds.  Van der Waals forces are existent within the chain itself, as well as the hydrogen bonding when the ergosterol is in the receptor site to the oxygen on the carbonyl group.  Some important bond angles in the molecule are as follows:

carbonyl --> tip of barrel = 21 angstroms

nitrogenous sugar --> tip of barrel = 20 angstroms

bedpost -OH --> bedpost -OH = 10 angstroms

-OH within receptor cavity --> C-17 on chain = 10.1 angstroms

side --> side = 4.6 angstroms

The most phenomenal bond length relationship is clearly the correlation of the distance between the bedpost -OH groups and the distance of the receptor cavity to which the ergosterol binds.  This clearly shows that this drug was made to operate and act on the sterol group, which in this case happens to be the ergosterol.