I’m an organic chemist, and I have been for fifteen years. I’ve worked in a lot of different places, including NASA and numerous universities. Throughout my career, I’ve always been very comfortable with the role that organic chemistry plays in studies of living organisms. Those outside the science field may not realize it, but chemistry is pretty tightly divided between five major fields: organic, inorganic, physical, analytical, and biochemistry. Physical chemistry is the study of why chemical reactions occur; it uses math to describe the “nuts and bolts” of molecular reactivity. Analytical chemistry is the forensic field. Analytical chemists use various tests and instrumentation to make statements about a chemical’s composition. Biochemistry is the study of the chemistry of living organisms. DNA, proteins, anything that is found inside a living object. Inorganic chemistry is the study of metals, primarily, although they dip all over the periodic table.
Organic chemistry is concerned with the chemistry of carbon. If it doesn’t have carbon in it, we organic chemists probably aren’t that interested in it. While it may seem very limiting to just pick one element out of the hundred plus that are available, carbon has a vast reactivity that makes it incredibly complex and difficult to learn. Organic chemistry is a hard subject, as many college students can tell you. I chose to study organic chemistry because it’s so applicable to every day life. If you look around you right now, the chances are extremely high (unless you’re in solitary confinement) that you’re going to be surrounded by organic objects. Plastics, pharmaceuticals, wood, fibers, paper, food, all of these are organic materials because they all contain carbon. Inorganic materials would include concrete, drywall, a soda can, your car keys, etc, because inorganic chemistry studies primarily metals and other non-carbon materials.
As you might imagine, there’s a large overlap between the fields of organic chemistry and biochemistry. Because our bodies and the systems of other living organisms such as plants are all carbon-based, organic chemistry is central to the study of a human blood cell, for example. As an organic chemist, I’m happy that the knowledge I have is so important and so relevant, because it means I can make educated decisions about healthcare and medications, not to mention the food I eat or the consumer products that I buy. To tell the truth, I’ve always felt a little bit sorry for inorganic chemists, because they are so scattered and they don’t have a central rallying point that’s relevant to such large fields as medicine and biology. However, I recently read an article in the journal Angewandte Chemie, which is a German science magazine that’s probably third in the world in terms of importance (after Science and Nature). A group of Scottish chemists report that they have created an entirely inorganic “cell”.
How is this possible? Well, the researchers created compartments out of polyoxymetallate membranes. These membranes had selective permeability towards certain small molecules, and could be nested inside one another. This allowed stepwise reactions to occur in a sequence, because each “layer” of membranes was an enclosed reaction vessel. The resulting cells had tunable morphology (meaning the shape could be varied). The cells showed redox activity, which meant that chemicals could be oxidized as well as reduced – an important set of reactions that occurs widely throughout a living cell. The cells also had chirality, meaning that they were oriented preferentially in one direction on the atomic level. This also mimics the behavior of living organic organisms. After reading the article carefully, I was a little bit skeptical that these objects could be called cells. A cell is so complicated, with all of the various internal structures, that these inorganic materials didn’t seem to match that level of sophistication. However, I’m forced to agree that the “cells” prepared by the Scottish group had numerous functions that mimicked a living cell. Maybe I’m just not ready to admit that organic chemists no longer have the entire field to themselves. It might be time for biochemistry to start listening to inorganic chemists; it seems they have something important to say.
The source of this article can be found at:
Cooper, G., et al. “Modular redox-active inorganic chemical cells”. Angewandte Chemie Int. Ed. Engl. 2011, 50, 10373-10376.