“Brilliantly, diligently,
Rosalind Franklin:
Her crystallographic skills,
Insights display;
Her expertise, honed
In X-ray diffraction:
Unwinds major mystery,
Reveals DNA.”
The next chemistry-themed poem in April 2020 was posted on April 16, in memory of Rosalind Franklin. Rosalind Franklin was a scientist whose expertise in X-ray crystallography revealed insights into several important chemical structures in the mid-twentieth century.
“Brilliantly, diligently, /
Rosalind Franklin: /
Her crystallographic skills, /
Insights display…”
Different energies and wavelengths of electromagnetic radiation (light) are used by scientists to understand different aspects of chemical behavior. X-rays have higher energies and shorter wavelengths than visible light. When X-rays shine onto a crystalline sample, they are diffracted into a characteristic pattern due to the arrangement of the atoms within the crystal. A crystallographer can observe this characteristic pattern and deduce the arrangement of atoms that must have caused that pattern.
Rosalind Franklin (1920-1958) used X-ray crystallography to observe chemical compounds for which the underlying structures were not yet known: demonstrating brilliance and diligence via her experimental and analytical skills.
“Her expertise, honed /
In X-ray diffraction: /
Unwinds major mystery, /
Reveals DNA.”
The most famous of these cases was that of deoxyribonucleic acid (DNA). DNA was isolated (experimentally separated) by biochemist Friedrich Miescher in 1869. Clarifying DNA’s structure required several more decades, via a path relying on both theory and experiment. Four scientists were responsible for the major insights in the early 1950s that revealed this structure’s now-famous double helix. Along with Franklin, Maurice Wilkins completed key crystallographic experiments; Francis Crick and James Watson devised the theoretical model explaining the structure.
Crick, Watson, and Wilkins received the Nobel Prize in Physiology or Medicine in 1962. Franklin had died of ovarian cancer in 1958 and did not share in the award. Much has been written about this, at much greater length.
Franklin’s scrupulous X-ray crystallographic work was crucial in understanding DNA’s structure: famously, her lab’s “Photo 51” demonstrated that the molecule contained a helix, “unwinding [the] major mystery” to “reveal DNA.”
Chemphasis 