This lecture covers the importance of organic chemistry in everyday compounds, such as poisonous alkaloids found in snowdrops, the role of galantamine in treating Alzheimer's disease, and the mechanism of nerve agent poisoning. It also delves into the principles of green chemistry, focusing on the twelve principles and their application in designing sustainable chemical processes. The lecture further explores the stability of reactive intermediates, the choice of hybridization in organic compounds, and the concepts of constitution, configuration, and conformation in organic molecules.