- Person
- Richard Willstätter
- Lived
- 1872–1942
- Field
- Organic chemistry
- From
- German
The story
At the start of the twentieth century, chlorophyll, the pigment that makes plants green and lets them turn sunlight into food, was poorly understood. It is fragile and easily altered during extraction, and earlier chemists had produced contradictory results. Was the green pigment of a fern the same as that of a nettle or an oak? Richard Willstätter, who became professor of chemistry at the ETH in Zurich in 1905, set out to answer the question systematically.
With his students he developed gentle methods for isolating chlorophyll from plant material without changing it or introducing impurities. He then examined chlorophyll from more than two hundred different kinds of plants. He found that it is essentially the same throughout the plant world. It is not one substance but two closely related ones: a blue-green pigment he called chlorophyll a and a yellow-green pigment he called chlorophyll b. In the plants he tested they occurred in a ratio of roughly three to one.
Sources differ slightly on where this landmark result was completed. Accounts of his Zurich years credit it to his time there, while his Nobel biography and the German Patent Office note that he rounded off his chlorophyll research with a team of collaborators in Berlin, after moving in 1912 to direct the Kaiser Wilhelm Institute for Chemistry. With his former student Arthur Stoll he summarised the work in a 1913 book, Untersuchungen über Chlorophyll, and between 1913 and 1919 he published twenty-five papers in a series on the pigment.
Willstätter also showed that both forms contain magnesium as an essential part of the molecule, and he produced a series of well-characterised breakdown products. This groundwork made possible the later complete determination of chlorophyll's structure by Hans Fischer. In 1915 Willstätter received the Nobel Prize in Chemistry for his research on plant pigments, especially chlorophyll.
The names Willstätter gave are still used in every biology textbook. The discovery that all green plants share the same basic light-harvesting chemistry was a major step in understanding how life captures the energy of the sun, and chlorophyll a and b remain central to the study of photosynthesis today.
Why it matters
Chlorophyll a and b remain central to plant science, agriculture and the study of photosynthesis, including research into more efficient crops and solar energy.
About Richard Willstätter
Nobel-winning chemist who unravelled chlorophyll and the colours of flowers, refused to convert, resigned his chair in protest at antisemitism and died a refugee in Switzerland.
More about Richard Willstätter
- Richard Willstätter helped explain why carrots are orangeWhile purifying chlorophyll, Richard Willstätter found yellow by-products that turned out to be carotenoids, beginning the scientific study of the pigments in carrots, tomatoes and egg yolks.
- Richard Willstätter decoded the colours of flowersRichard Willstätter discovered that most red, purple and blue flowers owe their colour to three related pigments, and that acidity or alkalinity in the sap helps decide the shade.
- Richard Willstätter corrected the structure of cocaineAs a young doctoral student in Munich, Richard Willstätter showed that the accepted chemical structure of cocaine was wrong, launching his career in the chemistry of plant alkaloids.
- Richard Willstätter made a molecule that tested a theoryRichard Willstätter synthesised cyclooctatetraene, a ring of eight carbon atoms, and showed it does not behave like benzene, an important test of ideas about chemical stability.
- Richard Willstätter treated enzymes as chemicalsIn the 1920s Richard Willstätter developed methods to purify enzymes and helped establish that they are chemical substances that can be studied with the tools of chemistry.
- Richard Willstätter built a gas mask filter in five weeksRefusing to work on poison gas, Richard Willstätter instead designed a protective gas mask filter in about five weeks in 1915, shielding soldiers from chlorine and phosgene.
- Richard Willstätter found magnesium at chlorophyll's heartRichard Willstätter showed that magnesium is an essential part of chlorophyll, the green pigment plants use to capture sunlight, work that won him the 1915 Nobel Prize in Chemistry.
- Richard Willstätter resigned to protest antisemitismIn 1924 Richard Willstätter gave up one of Germany's most prestigious chairs of chemistry in protest after his Munich colleagues refused to appoint a scientist because he was Jewish.
Sources
- Richard Willstätter Encyclopedia.com
- Richard Willstätter Wikipedia
- Richard Willstätter: Biographical NobelPrize.org
- Richard Willstätter, Great Inventors German Patent and Trade Mark Office (DPMA)
Another act of tikkun olam. This is part of tikkun olam, the Jewish idea of repairing the world, and every one of us can add to it.