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federico cinquepalmi
This definition was developed during the first half of the twentieth century by Hans Leo Kornberg2, working in collaboration with his colleague and friend Hans Adolf Krebs3. Such a definition can easily be applied to urban systems when they are considered as living organisms, based on flows of materials and energy exchange, both with the external environment and among their various internal components. Metabolic approaches to the urban context In the second half of the twentieth century a metabolic perspective on human settlements led to the definition of several innovative approaches which have allowed us to read cities as open systems characterized by a He was a contemporary and friend of Frank Lloyd Wright, Clarence Stein, Frederic Osborn, Edmund N. Bacon, and Vannevar Bush. 1 Kornberg, H. L. 1998, Metabolism (Biology), in Britannica. 2 Sir Hans Leo Kornberg, Fellow of the Royal Society, (1928 - 2019) was a German-born British-American biochemist. He was the “Sir William Dunn” Chair of Biochemistry at the University of Cambridge from 1975 to 1995 and Master of Christ’s College, Cambridge from 1982 to 1995. He is co-author of the text Energy Transformations in Living Matter (1957) and author of many papers on cellular metabolism. Krebs H. A., Kornberg L., 1957, Energy, Op. cit. 3 Sir Hans Adolf Krebs (1900 - 1981) was a German-born British biologist, physician, and biochemist who pioneered the study of cellular respiration, a biochemical process in living cells responsible for extracting energy from food and oxygen and making it available to drive life processes. He is best known for his discoveries of two important sequences of chemical reactions that occur in human cells and many other organisms, namely the citric acid cycle and the urea cycle. The former, known as the ‘Krebs cycle’, is the key sequence of metabolic reactions that provide energy to human cells and other oxygen-respiring organisms. His discovery earned Krebs the Nobel Prize in Medicine in 1953. With Hans L. Kornberg he also discovered the glyoxylate cycle, which is a slight variation of the citric acid cycle found in plants, bacteria, protists and fungi. Krebs died in 1981 in Oxford, where he spent 13 years of his career from 1954 until his retirement in 1967 at the University of Oxford.
