Cv: To explain the law of mass action + describe affinity & dissociation constants

LAW OF MASS ACTION states that the rate of a reaction is dependent on the [   ] of reagents

Binding of ligand with receptor:

KD = dissociation constant = [  ] when 50% of receptors is occupied

IF KD = low number → indicates less drug is required to occupy 50% receptors, implying each molecule is tightly associated with its receptor

 KA = association constant (reciprocal)

  • Measures the affinity of drug for receptor
  • When plotted on logarithmic scale
    • Receptor occupancy v. drug concentration
    • Relationship represents sigmoid curve