Source: Produced for Teachers' Domain
This video produced by Teachers' Domain features Cathy Drennan, Professor of Chemistry and Biology at the Massachusetts Institute of Technology. Cathy explains that her research focuses on microorganisms that live off carbon dioxide, one of several greenhouse gases that are widely believed to accelerate global warming. Specifically, Cathy is investigating how a protein inside these microorganisms converts carbon dioxide into energy. Ultimately, Cathy hopes humans might apply what they learn from microorganisms to remove carbon dioxide from the environment.
The bacterium Moorella thermoacetica, which thrive in the bottom of lakes and other oxygen-poor environments, produce a unique protein. In addition to the typical carbon, nitrogen, and oxygen atoms that compose the protein's amino acid chain are two metals: iron and nickel. Somehow these metals enable the protein to catalyze an intriguing chemical reaction: converting the carbon monoxide that's present in the bacteria's immediate environment into energy. This process has become the focal point of MIT scientist Cathy Drennan's research. Cathy reasons that if certain microorganisms can capture carbon gases and use them to make something else, then maybe scientists could engineer other microorganisms to perform a similar task in a different environment: removing carbon dioxide from Earth's atmosphere.
To better understand the chemistry underlying the metabolic processes, Cathy and her research team use biotechnology techniques to grow Moorella thermoacetica in the lab, break them open, and extract the protein of interest for further study. Cathy's team uses a technique called X-ray crystallography to bounce X-ray beams through crystals and form an electron picture of how the protein is assembled. By understanding the structure of the "metal-protein," Cathy might better understand how the special enzymes it produces catalyze the chemical reaction. And it's this fundamental understanding that might one day lead to the development of catalysts that lower carbon levels in the atmosphere.
Interestingly, Cathy Drennan did not always love the field of study she's working in now. In fact, she strongly preferred biology to chemistry. Here's what she has to say about her "turning point," and the lesson she passes on to others about it:
I did not like chemistry in high school, and I always would arrange my music lessons so that I could skip chemistry class.... Then I got to college, and I wanted to study biology or psychology. They said, "You have to take chemistry." And I said, "Oh no, I don't want to take chemistry again. Chemistry has nothing to do with biology." I was quite sure of that. And they said, "No, no, chemistry is actually the fundamentals of biology." I just couldn't believe that that was true based on my course, but I took it... and I just fell in love with it.
I really like knowing the fundamental details of why, and chemistry seemed to be truth to me. I wanted to understand biology, but I wanted to understand it at the molecular level. At the molecular level, it's chemical reactions that cause things to live. So if you dive deep down into biology, you find yourself to be a chemist. I hadn't made that connection in the beginning.
Now I'm a chemist, and I teach chemistry, and so I also like to say to students, never say you hate a subject because you might end up doing that thing for the rest of your life.