Willstätter, Richard Martin (1872-1942) was a German chemist who pioneered in the field of plant chemistry with his research into the structure of pigments in plants. In 1905, he began his research into chlorophyll, the green pigment in plants that absorbs light energy. This research included the process of photosynthesis, by which plants convert light into chemical energy. Willstätter was awarded the 1915 Nobel Prize in chemistry.
Willstätter was born in Karslruhe, Germany. He attended school in Karslruhe and then in Nuremberg after his family moved there. In 1890, he enrolled at the University of Munich, where he studied science under Nobel Prize-winning chemist Adolf von Baeyer. Willstätter studied the structure and synthesis of plant alkaloids, a group of organic bases found in plants. Alkaloids contain carbon, hydrogen, nitrogen, and oxygen. Some useful alkaloids are synthesized (artificially put together) in chemical factories, as well as taken from plants. Willstätter obtained his Ph.D. degree in chemistry in 1894. His doctoral research focused on the structure of cocaine, a powerful drug made from the leaves of the coca shrub. He remained at the University of Munich for 15 years. In 1896, he joined the department of chemistry and became a lecturer.
In 1905, Willstätter became a professor of chemistry at the University of Zurich. There he began his studies on chlorophyll, the green pigment in plants that absorbs light energy for use in photosynthesis. Most plant cells need light to produce chlorophyll. Chlorophyll is located in tiny cell bodies called chloroplasts. The chloroplasts in the leaves of plants carry out all the essential processes of photosynthesis, which is the food-making process that occurs in green plants. The chief function of leaves is photosynthesis, and green plants use energy from light to combine carbon dioxide and water to make food. All our food comes from this important energy-converting activity of green plants. Animals eat the plants, and people eat animal products as well as plants.
When Willstätter began researching chlorophyll, scientists did not fully understand its structure. Some thought that one plant could have multiple types of chlorophyll. Willstätter demonstrated that chlorophyll is made up of two components: chlorophyll a and chlorophyll b. By studying more than 200 plants, Willstätter showed that the chlorophyll produced by different plants shares a certain common chemical structure. His findings demonstrated that the process of photosynthesis uses the same set of chemical reactions in every plant.
After seven years in Switzerland, Willstätter came back to Germany in 1912 to take a position as professor at the Kaiser Wilhelm Institute of Chemistry in Berlin-Dahlem. He taught at the university from 1912 to 1916. There he did research on anthocyanins, the group of pigments, formed in the cell sap of plants, that produces the deep red, blue, lavender, and purple colors of petals, leaves, roots, or fruits. The colors seen in autumn foliage are produced by anthocyanins. Willstätter learned that the shades of color in a group of flowers are produced by only three anthocyanins with slight chemical differences. After the end of World War I (1914-1918), he studied enzymes, substances that speed up chemical reactions in living organisms. He proved that enzymes were chemical substances rather than biological organisms.
Willstätter's investigations of the enzymes involved in photosynthesis provided the basis for many later discoveries in modern biochemistry. The Nobel committee honored Willstätter with the Nobel Prize in chemistry in 1915 for his researches on chlorophyll and other plant pigments.
In 1916, Willstätter returned to Munich University. In 1924, however, he resigned from his post at the university in the face of anti-Semitic pressure. By 1938, anti-Semitic measures in Nazi Germany had become serious. In 1939, Willstätter had to flee, losing most of his property. He emigrated to Switzerland and moved to Locarno. There he wrote his autobiography, Aus meinem Leben (From My Life), published in 1949, after his death.
Willstätter won the Davy Medal of the Royal Society of London in 1932. He was a foreign member of the Royal Society of London and held honorary degrees from several top universities. He died on Aug. 3, 1942, in Locarno, Switzerland.