The quantitative differences in biological activity between the two enantiomers of a compound are sometimes quite large. for example, the d isomer of the drug isoproterenol, used to treat mild asthma, is 50 to 80 times more effective as a bronchodilator than the l isomer. identify the chiral center in isoproterenol. why do the two enantiomers have such radically different bioactivity?

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.

answers: to make sure that all of the broken pieces of tablet were added to the water, to allow for fair comparison of all three trials, with different particle sizes to avoid experimental error

c-14 is carbon-14, or radiocarbon.   it is a radioactive isotope of carbon with an atomic nucleus containing 6 protons and 8 neutrons.