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Women in Science: Dorothy Crowfoot Hodgkin's X-Ray Crystallography

Everyday Einstein discusses the accomplishments of English chemist Dorothy Crowfoot Hodgkin. Her research in X-ray lasers led to revolutionary treatments for bacterial infections, Alzheimer's, and diabetes. 

By
Sabrina Stierwalt, PhD
4-minute read
Episode #137

Scientists then measure the angles and intensities of these bent beams of light to get a 3D picture of the density of electrons in the crystal. The number of electrons, plus how closely packed together they are, reveals the positions of the different atoms within the crystal and how they are chemically bonded.

You can think of this decoding process like you would a Sudoku puzzle. While you can try to place numbers in certain boxes (or, in our case, atoms in certain formations within the crystal), ultimately, there is only one way the pieces can fit together to give you the final result.

The Pieces of the Penicillin Puzzle

Using X-ray crystallography, Dr. Hodgkin solved the structure of cholesterol in 1937, the structure of vitamin B12 (the largest and most structurally complicated vitamin) in 1956, and the structure of insulin in 1969, an endeavor she worked on for over 30 years!

Perhaps her greatest achievement, however, was solving the structure of penicillin in 1945. After doctors and scientists, starting with Alexander Fleming and Ernest Duchesne in the early 1900s, discovered that products of the mold called Penicillium could be used to effectively suffocate certain types of bacteria and keep them from multiplying, penicillin was soon being used to fight bacterial infections in people. Before the use of penicillin and other antibiotics, simple ear infections or even infected scrapes or cuts were potentially life threatening health issues.

The wonder drug still had its issues, however. Mass-producing penicillin was difficult and it had to be administered in large amounts since it was so easily excreted from the body. Roughly 80% of a dose of penicillin left the body only 3-4 hours after taking it. There was so much demand for the drug that doctors were even extracting it from patients' urine to be reused! (Luckily, production is no longer so hard and we no longer have to resort to such recycling.)

The structure of penicillin is also very complex and chemists at the time were having trouble cracking its crystalline code. Knowing its structure was particularly important since penicillin is most effectively used to fight infection when isolated in its pure state. Finally, in 1945 (when she was only 35!), Dr. Hodgkin was able to decipher how the carbon, hydrogen, oxygen, sulfur, and nitrogen atoms piece themselves together to make up the penicillin puzzle.

Dorothy Crowfoot Hodgkin won a well-deserved Nobel Prize in Chemistry in 1964 for her efforts.

What other contributions from female scientists do you encounter every day? Share them with Everyday Einstein on Facebook  or on Twitter where I’m @QDTeinstein.

Until next time, this is Sabrina Stierwalt with Everyday Einstein’s Quick and Dirty Tips for helping you make sense of science. If you have a question that you’d like to see on a future episode, send me an email at everydayeinstein@quickanddirtytips.com..

Molecule and woman scientist images courtesy of Shutterstock. Dorothy Crowfoot Hodgkin image courtesy of ScienceMuseum.org

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About the Author

Sabrina Stierwalt, PhD

Dr Sabrina Stierwalt earned a Ph.D. in Astronomy & Astrophysics from Cornell University and is now a Professor of Physics at Occidental College.