Hans Krebs (biochemist)

Hans Krebs was a great scientist.

He studied how living cells work. He found how cells get energy from food. Cells use food and air to make this energy. This process helps all living things stay alive.

He found a special cycle in our cells. This cycle is called the Krebs cycle. It helps cells get much more energy. He also found a different cycle called the urea cycle.

Because of his work, he won a Nobel Prize. This is a very big prize for science. He lived in many places like Germany and England. He also worked at a place called Oxford. He was a very important researcher.

Hans Krebs was a famous scientist. He studied how cells work. He was a biochemist. This means he studied the chemistry of living things.

He wanted to know how cells get power from food.

Krebs found two important ways cells work. The first is the citric acid cycle. We often call this the Krebs cycle. In this cycle, cells use oxygen to get power from food. This helps cells make much more power than other ways.

This big discovery won him a Nobel Prize in 1953.

The second way is the urea cycle. He found this with a student named Kurt Henseleit. This cycle shows how cells make urea. He also found the glyoxylate cycle. This is a different way that plants and fungi work.

Krebs was born in Germany. He had to move to England in 1933. He worked at many places. He spent many years at the University of Sheffield. Later, he worked at the University of Oxford.

He lived to be 81 years old.

Hans Krebs was a brilliant scientist who studied how life works at a tiny level. He was a biochemist, which means he studied the chemistry inside living things.

His main goal was to understand cellular respiration. This is the way cells take energy from food and oxygen to power life. Without this process, living cells could not do their jobs. Krebs discovered how cells turn food into the energy they need to stay alive. His work helped us understand the very basics of how all living things function.

Krebs discovered how cells use a special sequence of reactions to get energy. This is called the citric acid cycle, but many people call it the Krebs cycle. In this cycle, cells use oxygen to break down food like glucose. This method provides much more energy, called ATP, than other ways. He also found the urea cycle, which is how cells make urea.

Later, he and Hans Kornberg found the glyoxylate cycle in plants and fungi. This cycle is a slight variation of the citric acid cycle.

Krebs began his journey in Germany, where he was born in Hildesheim. He studied medicine at the University of Göttingen and the University of Freiburg. In 1926, he worked as an assistant to Otto Warburg in Berlin.

However, his life changed in 1933 due to his Jewish ancestry. The Nazi government removed him from his job in Germany. Luckily, Sir Frederick Gowland Hopkins helped him move to Cambridge, England. This move allowed him to continue his important research in a new country.

His discoveries led to many great honors and awards. In 1953, he won the Nobel Prize in Physiology or Medicine. He shared this prize with Fritz Lipmann for finding the citric acid cycle.

He also received the Albert Lasker Award in 1953. Throughout his career, he worked at the University of Sheffield and the University of Oxford. He spent 13 years at Oxford starting in 1954. He published over 100 research papers during his time there. He died in Oxford in 1981 at the age of 81.

We can see Krebs's work in almost every living thing today. The cycles he found happen in nearly all organisms, including humans. When you eat food, your cells use the Krebs cycle to turn that food into power. It is like a tiny engine running inside you right now. Even plants use a version of his work through the glyoxylate cycle. Understanding his work helps scientists learn how to keep living things healthy and strong.

Sir Hans Adolf Krebs was a pioneering German-British biochemist and physician. His work focused on cellular respiration, which is the process living cells use to extract energy from food and oxygen. This energy drives all the essential processes of life.

Krebs is most famous for discovering two vital sequences of chemical reactions. These include the citric acid cycle and the urea cycle. These cycles occur in the cells of nearly all organisms, including humans. His research helped scientists understand how life sustains itself at a molecular level.

One of his most significant discoveries was the urea cycle, also known as the Krebs–Henseleit cycle. In 1932, while working at the University of Freiburg, Krebs and his student Kurt Henseleit investigated how cells form urea. They built upon earlier work by scientists A. Kossel and H. D. Dakin. Krebs used a specialized manometer to measure oxygen consumption in liver tissue. By mixing liver slices with ornithine and citrulline, he proved that citrulline acts as a catalyst. This catalyst helps drive the metabolic reactions that turn ammonia and carbon dioxide into urea. This was the first metabolic cycle ever discovered.

Krebs also mapped out the citric acid cycle, often called the Krebs cycle. This cycle is the sequence of metabolic reactions used by oxygen-respiring organisms to obtain energy. It allows cells to produce much more ATP, or cellular energy, than anaerobic processes like glycolysis. Working at the University of Sheffield with William Arthur Johnson, Krebs tested many different chemical hypotheses. He used a manometer to see which molecules increased oxygen consumption in pigeon breast muscle. He identified key molecules like succinate, fumarate, and malate. By connecting these to earlier research on citrate and oxaloacetate, he established the full sequence. He submitted his findings to the journal Nature in June 1937.

In addition to these two major cycles, Krebs discovered the glyoxylate cycle. He performed this research in 1957 alongside Hans Kornberg. This cycle is a slight variation of the citric acid cycle. It involves two specific enzymes: malate synthase and isocitrate lyase. Malate synthase combines acetate with glyoxylate to create malate. Isocitrate lyase provides the glyoxylate by cleaving it from isocitrate. This pathway, known as the glyoxylate bypass, is found in plants, bacteria, protists, and fungi. It allows these organisms to use different metabolic routes than animals.

Krebs's career was marked by both great achievement and significant hardship. Born in Hildesheim, Germany, he studied medicine at the Universities of Göttingen and Freiburg. In 1926, he worked as a research assistant to Otto Warburg in Berlin. However, his life in Germany changed abruptly in 1933 due to his Jewish ancestry. The Nazi government passed laws that removed people of Jewish descent from professional jobs.

Fortunately, Sir Frederick Gowland Hopkins helped him move to the University of Cambridge. Krebs was able to bring his research equipment, including his vital manometer, to England. This equipment was essential for his future breakthroughs.

After moving to England, Krebs spent 19 years at the University of Sheffield. He became the first Head of the Department of Biochemistry there in 1938. His laboratory grew so large that local people nicknamed it "Krebs's Empire." In 1954, he moved to the University of Oxford as the Whitley Professor of Biochemistry. He remained at Oxford until his retirement in 1967. During his long career, he published over 100 research papers.

His dedication to science continued even after he retired from his official posts.

Krebs received many prestigious honors for his scientific contributions. In 1953, he was awarded the Nobel Prize in Physiology or Medicine. He shared this honor with Fritz Lipmann for their work on the citric acid cycle. That same year, he also received the Albert Lasker Award for Basic Medical Research. He was elected to the Royal Society in 1947 and was knighted in 1958. His impact on biochemistry is seen in the many distinguished scientists who worked under his leadership. He died in Oxford in 1981 at the age of 81.

The work of Hans Krebs connects our understanding of chemistry to the reality of biology. The cycles he identified are fundamental to how almost every living thing processes nutrients. By tracing how molecules like glucose and oxygen interact, he revealed the engine of life. His discoveries explain how energy is moved from the food we eat into the cells that power our bodies. This knowledge remains a cornerstone of modern biochemistry and medicine today.