This video tells us about the drug's action on the body and the receptors involved in the process of interaction of drug with the cell. TIMELINE: 0:03 Introduction 0:40 Receptors 0:55 Lock and key theory of working 1:08 Agonist 1:27 Antagonist 1:46 Partial agonist 2:04 Affinity 2:24 Examples (morphine-agonist)(naloxone-antagonist) 3:00 Conclusion