Answer:
The Chiral center is show in the figure
Explanation:
If a carbon atom is bonded to four differents groups as in isoproterenol (-OH, -Ph, -H and -CH2-R), it is a chiral carbon, which means that the molecule has two enantiomers, D and L.
Each enantiomer will have a different bioactivity, the bioctivity is the interaction of the D or L enantiomer with a biological receptor which also is chiral. The two enantiomers have different bioactivity because each one interact different with the biological receptor.
