The announcements of the 2013 Nobel Prizes continued this week, and while I want to give a shout-out to one of my favorite authors, Canadian Alice Munro, for her Nobel Prize in Literature win, I’ll be taking a closer look at this year’s winners in the chemistry category: Martin Karplus of Harvard University and the Université de Strasbourg in France, Michael Levitt of the Stanford University School of Medicine, and Arieh Warshel of the University of Southern California. They won the $1.25 million prize “for the development of multiscale models for complex chemical systems.”
Back in the day, chemists used models of molecules that looked a little more like what we used in science class — plastic balls joined together by sticks. While that was fun and all, it wasn’t super sophisticated.
Today’s chemists would snicker and turn back to their high-tech computer models. Without this year’s chemistry award winners, the computer modeling programs that mirror real chemical reactions might not exist, or at least, they might not be as awesome as they are. Karplus, Levitt, and Warshel figured out how to design programs that could map out the chemical processes involved in photosynthesis air and water purification, thereby illuminating these processes for more in-depth study.
The most important aspect of their work was the unification of classical Newtonian physics and quantum physics, which were thought to be mutually exclusive when it came to mapping and modeling molecules. Generally, scientists had to choose which kind of physics to use when studying molecular structures. Newtonian physics featured simper calculations, and was generally regarded as the best way to model big molecules. The problem was that classical physics couldn’t replicate or model chemical reactions. Chemists who wanted to study the reactions, which happen so quickly that scientists have historically struggled to see and understand them no matter how intently they focused on their test tubes, had to use quantum physics. But quantum physics is pretty complicated, and performing the calculations typically requires a lot of computational muscle, which generally limited it to small molecules.
The Nobel Laureates, whose work in this area began in 1972, united these two worlds of physics and figured out how to use them both. For example, in models designed to demonstrate a drug’s adherence to a protein, a computer would undertake the quantum physics, illuminating the drug’s effects on the atoms in the protein. At the same time, classical physics would be used to simulate the rest of the protein, providing chemists with the best of both worlds.
These days, computers are every bit as important in chemistry as test tubes, and computer simulations are so accurate that they can predict results. The ability to model and understand reactions that occur within enzymes, which regulate chemical reactions, has guided our understanding of the way living organisms and bodies work, as well as our development of drugs and other medical treatments.