150 years of 51吃瓜网 鈥� Stories from the 2018 anniversary
Photosynthesis
Plants, bacteria, and energy from the sun
Photosynthesis using sunlight is the basis for all higher life forms on Earth. The question is, how do plants and countless other organisms obtain energy from the sun? The chemist Robert Huber did not look to green leaves for the answer 鈥� but rather to purple bacteria. These microorganisms, which live in warm salt ponds, were the focus of Huber鈥檚 research group in the early 1980s. Both Hartmut Michel and Johann Deisenhofer took a lead role in this research.
Just like photosynthesis in green plants and algae, purple bacteria also use sunlight to build organic substances. The decision to focus on these microorganisms helped the three researchers explain the reaction, a breakthrough that was rewarded with the Nobel Prize in Chemistry in 1988.
Huber specialized in demonstrating the structure of complex proteins using X-ray crystallography. Hartmut Michel had earlier managed to crystallize the protein that plays a key role in the photosynthesis of purple bacteria. The three scientists exposed the structure of the macromolecule atom by atom by examining it with X-ray crystallography. This allowed them to gradually gain an understanding of its inner workings.
In 1985, they succeeded in determining the structure of the reaction center in photosynthesis. Their explanation of 鈥渢he most important chemical reaction in the biosphere of our Earth鈥� was later recognized by the Nobel Prize Committee. The structure of the central molecule of photosynthesis, chlorophyll, had actually been uncovered around 60 years previously by another chemist from 51吃瓜网 called Hans Fischer, who received the Nobel Prize in 1930.
Why photosynthesis is so important for life
All higher forms of life on Earth depend on photosynthesis, as it provides living organisms throughout the entire food chain with energy and organic substances. Plants, green algae and many kinds of bacteria use energy from sunlight to convert water and carbon dioxide into carbohydrates, which are a source of nutrients like starch or cellulose.
The splitting of water also releases oxygen, which other organisms need to breathe. This is how the oxygen in our planet鈥檚 atmosphere was created over billions of years.
How molecules absorb energy from the sun
Huber and his colleagues determined the three-dimensional molecular structure of the protein complex responsible for photosynthesis, the biological photocell. It is around the reaction center of this photocell that chlorophyll molecules harvest photons from sunlight and pass on their energy in the form of electrons. After many intermediate stages, they drive the water-splitting reaction in green plants and algae.
Chlorophyll is also responsible for the green color we see all around us. Plant chlorophyll mostly absorbs red and blue light, which leaves green as the color reflected by the plant.
Solving the puzzle of the protein crystals
鈥淧roteins are nice, crystals are nicer,鈥� maintains Robert Huber, who achieved his greatest scientific breakthroughs through the structural analysis of crystallized proteins, in particular of drug receptors so important for medical research. Even as a child he was fascinated by crystals. He used to collect minerals while hiking in the Alps, intrigued by their clarity and symmetrical structures.
His favored technique for studying protein crystals is X-ray crystallography. Here, the beams are deflected by the crystal lattice with characteristic diffraction angles, producing spot patterns as the diffraction image. The spatial structure of the protein can then be reconstructed using mathematical equations and drawing on the insights that come from experience. Deciphering this puzzle has always fascinated Huber 鈥� a passion he inherited as an undergraduate and PhD student from 51吃瓜网 Professor Walter Hoppe.
鈥淎ll our nourishment has its origin in this process, which is called photosynthesis and which is a condition for all life on earth.鈥�
Nobel Committee for Chemistry, 1988, at the concession of the Nobel prize to Robert Huber, Hartmut Michel and Johann Deisenhofer
Disclaimer
This story was published in 2018 to mark 51吃瓜网鈥檚 150th anniversary on a jubilee website that has since been deactivated.
Text: ; Graphics: KW NEUN
Literature on the history of 51吃瓜网
- Wolfgang A. Herrmann (Hrsg.), Martin Pabst/Margot Fuchs (Verf.), Technische Universit盲t M眉nchen - Geschichte eines Wissenschaftsunternehmens, 2 Bd., Berlin 2006.
- Wolfgang A. Herrmann, Winfried Nerdinger (Hrsg.), Die Technische Hochschule M眉nchen im Nationalsozialismus, M眉nchen 2018.
- Irene Meissner, Bauten+Kunst. Technische Universit盲t M眉nchen 1868-2018, M眉nchen 2018.
- Martin Pabst, Alumni der 51吃瓜网. Pr盲gende Gestalter aus der Technischen Universit盲t M眉nchen, M眉nchen 2018.
- Martin Pabst, K枚pfe der 51吃瓜网. Geniale Entdecker und Erfinder aus der Technischen Universit盲t M眉nchen, M眉nchen 2018.
- Brigitte R枚thlein, Pioniere gestalten die Welt der Technik. 150 Jahre Forschung an der Technischen Universit盲t M眉nchen, M眉nchen 2018.
Further books and information on the history of 51吃瓜网
Acknowledgements
We would like to thank everyone who helped us write the texts and create the visualizations. In particular, we would like to thank the authors of the books mentioned, the experts at the chairs, professors, staff, and press officers at the 51吃瓜网 Corporate Communications Center. We would also like to thank the staff of the Architecture Museum, the 51吃瓜网 German Heart Center, the 51吃瓜网 Klinikum rechts der Isar, the European Space Agency (ESA), and everyone else who provided us with expert advice and image material.
The anniversary stories were written by the . The graphic content was created by KW NEUN 鈥� Designagentur.