Robert H. Grubbs, winner of the Nobel Prize in chemistry in 2005, discusses the organic reaction of metathesis in which chemists selectively strip out certain atoms in a compound and replace them with atoms that were previously part of another compound. This results in a custom-built molecule that has specialised properties that can lead to better drugs for the treatment of disease. Metathesis is an organic reaction in which chemists selectively strip out certain atoms in a compound and replace them with atoms that were previously part of another compound. The end result is a custom-built molecule that has specialized properties that can lead to better drugs for the treatment of disease, or better electrical conducting properties for specialized plastics. Prior to Professor Grubbs’ work, metathesis was poorly understood and of limited value to scientists. Metathesis has already led to industrial and pharmaceutical methods that are more efficient and less wasteful, simpler, and more environmentally friendly.