biochemistry


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Friedrich Wöhler is considered a pioneer in organic chemistry. He was the first to succeed in synthesizing oxalic acid and urea , previously only known from living organisms, from inorganic starting compounds.

The Biochemistry (from Greek βιο-χημεία bio-chēmeia , "The Chemistry of Life") or Biological Chemistry , formerly Physiological Chemistry called, is the study of chemical processes in living organisms , the metabolism . Chemistry , biology and medicine are closely interlinked in biochemistry. The elucidation and healing of metabolic diseases, e.g. B. Hormone deficiency (e.g. diabetes ) and vitamin deficiency were made possible by biochemistry.

object

Structure of hemoglobin - a widely used biomolecule

Biochemistry deals with:

  • the investigation of biomolecular structures: how are the biomolecules constructed, what is the molecular structure of the organism of living beings, how are the molecular building blocks provided and how do they interact with each other?
  • the investigation of the metabolism: which substances are converted by living things and how, which bioenergetic prerequisites are necessary, which biocatalysts are involved, how do the respective mechanisms of metabolism run and how is the metabolism controlled?
  • the investigation of the exchange of information within an organism and between organisms: how is information stored, accessed and passed on, how are different systems within a cell, between different cells and between organisms coordinated?

In the course of this, the considerations concentrate on the organic substance groups of nucleic acids , proteins , lipids and other carbohydrates and their derivatives , which are generally referred to as biomolecules . The majority of the biochemically important processes take place in living beings and thus in an aqueous environment.

Methods

A multitude of methods from different areas are used in biochemistry. Classical biochemistry mainly uses analytical chemistry , organic chemistry , physical chemistry and physics . Important techniques are (ultra-) centrifugation , ultrasonic digestion , SDS gel electrophoresis , chromatography , electrophoresis , spectroscopy , radioactive labeling ( Tracer (nuclear medicine) ), isotopic techniques , crystallization , potentiometric , electrometric , polarographic and manometric techniques, cell wall breaking by cooling, Ames -Test in the last few decades, molecular biological methods and methods from computer science , microbiology and other subjects were added. In addition, in modern biochemistry there is always the quantitative evaluation of the results with mathematical methods and the formation of formal theories with the help of mathematics.

history

Hohentübingen Castle Laboratory, around 1870, one of the earliest biochemical laboratories, current permanent exhibition "Tübingen Castle Laboratory. Cradle of Biochemistry", Museum of the University of Tübingen MUT
Justus von Liebig in his laboratory in 1840, a time when the subject of biochemistry was still called physiological chemistry . Six years later von Liebig discovered the amino acid tyrosine .
In the 19th century people began to be interested in the chemical composition of gallstones. Clinical references to the occurrence of stones, preferably in women and in obesity, are established and systematically examined. The early biochemists recommend plant foods for prevention.
From 1820 onwards, the goiter was cured by means of biochemical research. In the beginning there was the gift of iodine . It was not until 1926 that the connection with hormones was recognized.
Eduard Buchner received the Nobel Prize in 1907 for his biochemical research.
Frederick Banting needed more than ten test dogs until insulin was proven and discovered as a cure for diabetes in 1921.

Beginnings

Since the beginning of the 19th century, organic chemists have been systematically investigating the composition of animals and plants and, from around 1840, also complex metabolic processes. It was possible to determine the carbon, hydrogen, nitrogen and sulfur content of biological material through elemental analysis. From 1860 onwards, chemical structural formulas of substances could be determined from their elementary composition through a combination of ideas, now a thorough search for the biological bodies in organisms began. The search was very time-consuming and not always successful due to the very small amount of biomolecules and the inadequate detection methods - even the elemental analysis required larger amounts of material. It was only with the improvement of analytical equipment from 1950 onwards that the search for and structure elucidation of biomolecules became easier. One of the world's first biochemical - then physiological-chemical - laboratories was set up in 1818 in the former kitchen of Hohentübingen Castle ( Eberhard Karls University of Tübingen ) by Georg Carl Ludwig Sigwart and Julius Eugen Schlossberger . Hemoglobin was discovered in it by Felix Hoppe-Seyler in 1861 and nucleic acid by his student Friedrich Miescher in 1869.

The Department of Physiological Chemistry split in 1922 from the physiology from. However, the foundations for physiological chemistry were laid earlier, for example around 1840 by Joseph von Scherer , the founder of clinical chemistry .

Proteins and fats

Fats were examined by Eugène Chevreul and later by Heinrich Wilhelm Heintz . Gerardus Johannes Mulder was able to produce a gelatinous precipitate from the fibrin of the blood and gave it the name protein. Louis-Nicolas Vauquelin examined the composition of the hair and found the chemical elements carbon, hydrogen , nitrogen , oxygen and sulfur there .

amino acid

Pierre Jean Robiquet and Louis-Nicolas Vauquelin also found the first amino acid, which they isolated in 1805: asparagine . Joseph Louis Proust discovered leucine (1818), Justus von Liebig discovered tyrosine (1846). Another 12 amino acids were discovered between 1865 and 1901, of which Ernst Schulze discovered three new amino acids: glutamine , phenylalanine and arginine . The first peptide syntheses were undertaken by Emil Fischer in 1901.

Justus Liebig realized that the yeast must contain a special substance that triggers fermentation. He called this substance bios . The term biochemistry was used for the first time when Vinzenz Kletzinsky (1826–1882) had his Compendium of Biochemistry printed in Vienna in 1858 . Felix Hoppe-Seyler ( lactic acid from glycogen , oxidation - and reduction enzymes , hemoglobin ), Georg Carl Ludwig Sigwart ( analysis of gall - and urolithiasis ), Anselme Payen (1833: amylase ), Julius Eugen Castle Berger ( creatine , hemocyanin ) extended the biochemical Knowledge.

Enzymes

Was discovered amylase (then Diastase) in 1833 by the French chemist Anselme Payen in a Malzlösung. This made diastase the first enzyme to be found.

At the beginning of the 19th century it was also known that the fermentation of dead organisms required oxygen from the air, and that temperature and water also had an influence on this process. In dead animals and people, putrefaction first begins in those areas that come into contact with the air. Chemists, above all Louis Pasteur , recognized fermentation processes in the case of vegetable matter, the formation of alcohol from a grape juice solution or the acidification of milk . During the investigation of the economically important fermentation of sugar into alcohol by yeast, Pasteur discovered that this was not due to putrefaction and dead organisms, as was usually assumed until then, but that it is a process in living organisms that use ferments (enzymes) for this. The body that facilitated these processes was called ferment . Eduard Buchner discovered cell-free fermentation in 1896. James Batcheller Sumner isolated the sword bean enzyme in 1926, claiming that all enzymes must be proteins.

A few years later , John Howard Northrop isolated pepsin , trypsin and chymotrypsin in crystalline form and was able to confirm Sumner's hypothesis.

nucleic acid

The physiologist Friedrich Miescher discovered the nucleoproteins in the cell nucleus in 1869. Albrecht Kossel discovered the nucleic acid adenine (1885). He obtained further nucleic acids from animal extracts, namely guanine , xanthine (1893), thymine (1894), cytosine and uracil (1903). Emil Fischer achieved the first syntheses of adenine, theophylline , thymine and uracil (1897–1903). Phoebus Levene investigated the linkage of a nucleic acid with a pentose and a phosphate to form the mono- nucleotide (1908).

carbohydrates

Carbohydrates are an important part of our diet, so they were studied by biochemists at an early stage. Both starch and sugar are broken down into glucose and, if there is an excess, are stored as glycogen in the liver . A constant blood sugar level is essential for the brain and muscles. Adolf von Baeyer gave the first formula for glucose in 1870. From 1887 Emil Fischer carried out extensive research to elucidate the chemical structure of sugars with phenylhydrazine to easily crystallize osazones . In 1893, by converting glucose with methanol to methyl glycoside - which did not reduce Fehling's solution - he was able to prove that the aldehyde group in the ring is linked to a hydroxyl group (glycosidic). Later (1922) Burckhardt Helferich concluded that the glucose had to be in a six-membered ring (1,5-glycosidic instead of 1,4-glycosidic). Norman Haworth did other important work on sugar chemistry and its structural representation ; he also synthesized vitamin C for the first time ( scurvy occurs in deficiency ), an acid derivative of sugar.

Vitamins

In the beginning of the 20th century, many people died from poor nutrition. In 1882 Gustav von Bunge examined rats and mice that he fed only protein, carbohydrates and fats, but whose diet contained no other additives. The animals died. In addition to protein, carbohydrates and fats, people also need vitamins. Many vitamins were found at the beginning of the 20th century. The structure elucidation of cholesterol (and thus of the group of steroids ) by Adolf Windaus was important for the structure elucidation and formation of vitamin D (when it is deficient, rickets occurs). Windaus was also involved in the elucidation of the molecular formula and structure of vitamin B1 . Sir Frederick Gowland Hopkins , a pioneer in biochemistry in Great Britain, and Casimir Funk , who coined the word vitamin , did important research into the discovery of vitamin B1 ( beri-beri occurs in deficiency ). Hopkins also discovered two essential amino acids and was awarded the Nobel Prize for them in 1929. In 1926 Otto Warburg discovered the respiratory enzyme cytochrome oxidase , a ferment in the citric acid cycle and for redox processes in cells, for which he received the Nobel Prize in 1931.

Hormones

Groups of substances that are produced in human organs are called hormones according to Ernest Starling . In 1849, Thomas Addison discovered a disease that originated in the adrenal glands. T. B. Aldrich and Takamine Jōkichi (1901) extracted a substance they called adrenaline from animal kidneys. Aldrich determined the empirical formula and Friedrich Stolz succeeded in chemical synthesis (1904). In 1904, biochemistry succeeded for the first time in the artificial production of a hormone .

The goiter is another hormonal disease of the thyroid , by since 1820 by Jean-Francois Coindet Iodgaben could be mitigated. It was not until 1915 that Edward Calvin Kendall succeeded in isolating a crystalline substance from the thyroid. He mistakenly thought it was an oxindole derivative and therefore called it thyroxine . Thyroxine has been synthesized by Charles Robert Harington since 1926 .

In 1935 Ernst Laqueur isolated what he called the sex hormone testosterone from bull testicles . The sex hormones were also examined by Adolf Butenandt . In 1929 he isolated one of the female sex hormones, estrone . Two years later he isolated a male sex hormone called androsterone . In 1934 he discovered the hormone progesterone . Through his research, it has been shown that the sex hormones are closely related to steroids . His research in the field of sex hormones enabled the synthesis of cortisone as well as other steroids. This eventually led to the development of modern contraceptives.

The deficiency of the pancreatic hormone could be alleviated by giving bovine insulin in 1920 by Frederick Banting and Best. It was not until 1953 that the amino acid sequence of insulin was cleared up by Frederick Sanger .

Important research areas in modern biochemistry

In biochemistry textbooks, the processes of fermentation from sugar to ethanol and lactic acid as well as the structure of glucose to glycogen are described in detail. These conversions are summarized under the keyword glycolysis .

The energy production in living cells takes place via the breakdown of fats, amino acids and carbohydrates via oxaloacetate to citrate via acetyl-S-CoA with the release of carbon dioxide and energy. Acetyl-S-CoA contains a water-soluble vitamin - pantothenic acid . This process was investigated by H. Krebs in 1937 and is called the citric acid cycle .

Oxidation of biomolecules in cells takes place via several enzymes in which vitamin B2 is involved. This process is described in textbooks as oxidative phosphorylation or respiratory chain .

Another biochemical process is photosynthesis . Carbon dioxide from the air and water is converted into carbohydrates and oxygen by radiation energy through the pigment chlorophyll in plant cells and phototrophic microorganisms.

In human and animal organisms, excess energy from food is stored in the form of fats. If the cells lack energy, these fats are broken down again. This process takes place via the oxidation of fatty acids using acetyl-CoA.

In the event of illness (severe diabetes) or extreme lack of food, cells also use amino acids for energy production. Proteins are broken down into amino acids and these are broken down into carbon dioxide. The urea cycle describes the conversions that take place.

In plant and animal cells, carbohydrates can be built up biochemically from other substances - for example lactic acid or amino acids. The studies on the individual biochemical steps are examined in gluconeogenesis . Furthermore, the biosynthesis of amino acids , nucleotides , porphyrins and the nitrogen cycle in plants have been thoroughly investigated.

Another sub-area of ​​biochemical research is the absorption and transport of metabolic products through the blood plasma.

The transfer of the information stored in the cell nucleus on the DNA (more precisely: certain sections of the DNA, the genes ) for the production of enzymes takes place via replication , transcription and protein biosynthesis . This is a very important area of ​​synthetic biochemistry ( biotechnology ) as bacteria can be made to produce certain enzymes on their cyclic DNA ( plasmids ).

Individual proteins can be detected using gel electrophoresis . The amino acid sequence of the protein can be determined by the Edman degradation .

Milestones in biochemistry

The citric acid cycle  - a biochemical metabolic pathway

19th century

20th century

Research institutes in the German-speaking area

(The lists are incomplete)

The Center for Chemistry and Biomedicine (CCB) am Innrain in Innsbruck

Max Planck Institutes and Leibniz Institutes

Leading in biochemical research are, for example, the Max Planck Institutes of the Max Planck Society , but also the Leibniz Institutes of the Leibniz Association :

University institutes and faculties

Biochemistry is an integral part of university education in the natural sciences. Doctors and biologists in particular, but also other natural scientists, devote themselves to the subject at universities. There are institutes for biochemistry at many German-speaking universities:

In Germany:

In Austria:

In Switzerland:

structure

Depending on the perspective, biochemistry is referred to as medical biochemistry in relation to human diseases , ecological biochemistry in relation to ecosystems , plant biochemistry in relation to plants, immunobiochemistry in relation to the immune system, and neurochemistry in relation to the nervous system . Likewise, the biochemistry is divided into groups of substances, e.g. B. protein chemistry , nucleic acid biochemistry , carbohydrate biochemistry and lipid biochemistry . Small molecules are treated by natural product chemistry . The enzymology and the signal transduction provide special areas is biochemistry. The Biophysical Chemistry analyzed biomolecules and living organisms using methods of physical chemistry .

Nobel Prize Winner in the field

In the gallery below you can find a selection of important Nobel Prize winners who have been awarded for research in the field of biochemistry (or its immediate neighboring disciplines):

biochemist

Education

In 2008, there were courses in biochemistry in Germany leading to a diploma , bachelor's and master's degree . The diploma courses are gradually being replaced by consecutive Bachelor and Master courses:

  • The biochemistry diploma course has a standard period of study of 9 to 10 semesters , a maximum period of 13 to 14 semesters and leads to the professional qualification of a diploma biochemist .
  • The bachelor's degree in biochemistry has a standard study time of 6 to 8 semesters and leads to the professional qualification Bachelor of Science - Biochemistry .
  • The master’s degree in biochemistry has a standard period of 3 to 4 semesters after the bachelor’s degree and leads to the professional qualification Master of Science - Biochemistry .

In addition to studying biochemistry, there is also the option of studying chemistry or biology and deepening the subject canon of biochemistry during the course. A specialization usually takes place through biochemistry as an elective or major subject as well as the preparation of a diploma, bachelor or master thesis in the field of biochemistry. This variant offers the advantage that first-year students do not have to decide directly on a pure biochemistry course. Rather, they have the opportunity to get to know various subjects in the basic course in order to then specialize during the main course, e.g. B. in biochemistry. The opportunity to do this is given at many universities and the standard study times correspond to those of the pure biochemistry courses. In the bachelor's and master’s degree programs, a variety of degree programs with different names and specializations has become established in the field of biosciences . What they have in common is that they attach particular importance to the molecular basis and have a high practical component in their training (see web links). In addition, a large part of the (basic) studies usually overlaps with the courses in chemistry and biology , but often also shows decisive differences (e.g. less specialization in botany , zoology or inorganic chemistry than in chemistry or biology studies). In the curriculum of the degree programs, special emphasis is placed on the modules in organic chemistry , physical chemistry and biochemistry, as these represent a basic knowledge required for working as a biochemist.

The specialist in biochemistry

There is also the possibility of becoming a specialist in biochemistry after completing a medical degree in Germany . This requires a four-year training period. Can be counted towards this

As of December 31, 2010, 102 biochemistry specialists were registered, one of whom was a resident. 52 did not practice any medical activity. The number of registered medical specialists for biochemistry fell by almost 50% within the decade 2000–2010.

See also

Portal: Biochemistry  - Overview of Wikipedia content on the subject of biochemistry

literature

Textbooks

History of organic chemistry and biochemistry

  • Graeme K. Hunter: Vital Forces. The discovery of the molecular basis of life. Academic Press, London 2000, ISBN 0-12-361811-8 (English)
  • Paul Walden : History of organic chemistry since 1880, Springer-Verlag, Berlin * Heidelberg * New York 1972, ISBN 3-540-05267-4
  • Uschi Schling-Brodersen: Biochemistry. In: Werner E. Gerabek , Bernhard D. Haage, Gundolf Keil , Wolfgang Wegner (eds.): Enzyklopädie Medizingeschichte. De Gruyter, Berlin / New York 2005, ISBN 3-11-015714-4 , p. 182 f.

Biochemical dictionaries

  • Peter Reuter: Pocket Dictionary of Biochemistry. German - English / English - German . Birkhäuser Verlag, Basel / Boston / Berlin 2000, ISBN 3-7643-6197-2 .

Teaching materials on the Internet

Biochemical journals

Web links

Commons : Biochemistry  - Collection of images, videos and audio files
Wikibooks: Biochemistry and Pathobiochemistry  - Learning and Teaching Materials
Wiktionary: Biochemistry  - Explanations of meanings, word origins, synonyms, translations

Individual evidence

  1. Martin Sperling: Specialization in medicine as reflected in the history of Würzburg. In: Würzburg medical history reports. Volume 3, 1985, pp. 153-184, here: p. 166.
  2. Dankwart Ackermann : On the development of physiology in Würzburg. In: Reported to the Physico-Medical Society of Würzburg. Volume 62, 1939, pp. 32-38.
  3. Chevreul: Recherches chimiques sur les corps gras d'origine animale , Paris 1823.
  4. ^ Journ. pr. Chemistry, 68 , 1.
  5. ^ Reports of the German Chemical Society 17 , 1610 (1884)
  6. Reports of the German Chemical Society 40 , 1755, 1764 (1907)
  7. Reports of the German Chemical Society 35 , 3226 (1902).
  8. ^ Lehninger Grundkurs Biochemie , Walter de Gruyter (1983), p. 65.
  9. Reports of the German Chemical Society 18 , 79, (1885).
  10. Reports of the German Chemical Society 26 , 2754 (1893).
  11. Reports of the German Chemical Society 27 , 2221, (1894).
  12. Hoppe Seylers Zeitschrift für Physiologische Chemie 38 , 49 (1903).
  13. ^ Reports of the German Chemical Society 30 , 553, 2226 (1897).
  14. Reports of the German Chemical Society 34 , 3751 (1901).
  15. Reports of the German Chemical Society 42 , 335, 2469, 2474 (1909).
  16. ^ Reports of the German Chemical Society 3 , 66 (1870).
  17. Reports of the German Chemical Society 20 , 821 (1887).
  18. Reports of the German Chemical Society 26 , 2400 (1893).
  19. ^ Reports of the German Chemical Society 56 , 759 (1923).
  20. Kurt Schlösser: Kurzzeit Elektrophoresis , Chemie in our time (February 1971), pp. 28-29.
  21. loeffle1: Welcome - Philipps University Marburg - Institute for Physiological Chemistry. In: uni-marburg.de. Retrieved December 23, 2016 .
  22. ^ Sylvia Rechel, Daniela Höcke: Institute for Biochemistry . In: Name of the department . ( charite.de [accessed December 23, 2016]).
  23. ^ Biochemistry - University of Greifswald. In: biochemie.uni-egoswald.de. University of Greifswald, accessed on June 1, 2018 .
  24. ^ Institute for Biochemistry. In: Institute of Biochemistry - Johann Wolfgang Goethe University. Accessed July 7, 2019 .