Rosalind Franklin: DNA's unsung hero - Cláudio L. Guerra
1,589,041 Views
42,870 Questions Answered
TEDEd Animation
Let’s Begin…
The discovery of the structure of DNA was one of the most important scientific achievements in human history. The now-famous double helix is almost synonymous with Watson and Crick, two of the scientists who won the Nobel prize for figuring it out. But there’s another name you may not know: Rosalind Franklin. Cláudio L. Guerra shares the true story of the woman behind the helix.
Additional Resources for you to Explore
Rosalind Franklin had a life full of challenges, not just scientifically but socially. She had to fight prejudice in an environment dominated by men in a time when women were presumed to be housewives and nothing more. Her success was recognized by many of her peers, but in the race for the structure of DNA and the recognition of key innovators in this field, sexism played a major role.
Years after her death, Brenda Maddox and Anne Sayre worked on biographies about Franklin and could clarify some aspects of her history that might otherwise have gone overlooked. Maddox’s work gave rise to an interesting documentary by PBS’ NOVA called Secret of Photograph 51.
Interested in learning more about early work on DNA? You can watch Watson's talk here: How we discovered DNA. Then check out the original Photo 51 here.
Franklin also did extensive work on crystallography - but what does this mean? Molecules like DNA are way too small to be seen by optic microscopes, and electron microscopes can't give a resolution that's good enough for us to see the structure of the molecules. In order to see these tiny details we can use x-ray crystallography. Crystals are solid materials in which the constituents are orderly arranged in a 3-D structure that repeats itself in all directions.
When crystallographers want to study a molecule, they take an x-ray of a crystal made from that molecule, pretty much like a doctor's or dentist's x-ray. The x-rays then interact with the atoms in the crystal, and because a crystal is a repeating pattern, the interaction is amplified many, many times. The resulting image is the sum of waves that are strengthened when they're in phase and weakened when they're out of phase. That way, the sum of positive interactions forms the final image and a computer program can calculate the positions of every atom from the positions of the dots.
Years after her death, Brenda Maddox and Anne Sayre worked on biographies about Franklin and could clarify some aspects of her history that might otherwise have gone overlooked. Maddox’s work gave rise to an interesting documentary by PBS’ NOVA called Secret of Photograph 51.
Interested in learning more about early work on DNA? You can watch Watson's talk here: How we discovered DNA. Then check out the original Photo 51 here.
Franklin also did extensive work on crystallography - but what does this mean? Molecules like DNA are way too small to be seen by optic microscopes, and electron microscopes can't give a resolution that's good enough for us to see the structure of the molecules. In order to see these tiny details we can use x-ray crystallography. Crystals are solid materials in which the constituents are orderly arranged in a 3-D structure that repeats itself in all directions.
When crystallographers want to study a molecule, they take an x-ray of a crystal made from that molecule, pretty much like a doctor's or dentist's x-ray. The x-rays then interact with the atoms in the crystal, and because a crystal is a repeating pattern, the interaction is amplified many, many times. The resulting image is the sum of waves that are strengthened when they're in phase and weakened when they're out of phase. That way, the sum of positive interactions forms the final image and a computer program can calculate the positions of every atom from the positions of the dots.
About TED-Ed Animations
TED-Ed Animations feature the words and ideas of educators brought to life by professional animators. Are you an educator or animator interested in creating a TED-Ed Animation? Nominate yourself here »
Meet The Creators
- Educator Cláudio L. Guerra
- Script Editor Eleanor Nelsen
- Director Chris Bishop
- Animator Chris Bishop
- Narrator Susan Zimmerman
