Structural Biochemistry/History
First step in organic synthesis
[edit | edit source]The synthesis of an organic substance took place in 1828 by Friedrich Wohler, who synthesized urea. This marked the first synthesis of an organic natural product, signifying the beginning of the branch of organic chemistry as it is known today. The discovery of the enzyme diastase (today known as amylase) in 1833 by Anselme Payen is similarly regarded as the beginning of the branch of biochemistry.
Although a number of biological processes, such as the conversion of starch to sugars by saliva, had been previously observed, the exact mechanism behind these processes was unknown. The 19th century scientist Louis Pasteur hypothesized that the fermentation process was catalyzed by a "vital force" by studying the conversion of sugars to alcohol by yeast. He called this vital force "ferments," and he recognized that the observed conversion took place only within living cells. This marked one of the first instances in which a scientist acknowledged the possible existence of a set of sub-cellular machinery that had the ability to bring about the transformation of one chemical to another.
19th century
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The discovery of the first enzyme, diastase in 1833 by Anselme Payen, may have marked the beginning of biochemistry. Although the term “biochemistry” seems to have been first used in 1882, it is generally accepted that the formal coinage of biochemistry occurred in 1903 by Carl Neuberg, a German chemist. Previously, this area would have been referred to as physiological chemistry.
Since then, biochemistry has advanced greatly, especially since the mid-20th century, with the development of new techniques such as chromatography, X-ray diffraction, NMR spectroscopy, radioisotopic labeling, electron microscopy and molecular dynamics simulations. These techniques have allowed for the discovery and detailed analysis of many molecules and metabolic pathways of the cell, such as glycolysis and the Krebs cycle (citric acid cycle).
In 1878, Wilhelm Kühne came up with the word "enzyme" to describe the fermentation process that Pasteur observed. The use of the word enzyme has changed since its inception; it is now used to describe biomolecules that catalyze biological processes.
In 1897, Eduard Buchner began to investigate the peculiar ability of yeast extracts to ferment sugars to alcohols in the absence of living yeast cells. A series of experiments led to the conclusion that an enzyme found in the yeast extract was catalyzing the reaction; he called this enzyme "zymase". The idea that enzymes could function outside of a living cell was revolutionary, and in 1907 Buchner was awarded the Nobel Prize in Chemistry for his discovery.
20th century
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In 1912, Sir Frederick Gowland Hopkins published his seminal paper, "Feeding Experiments Illustrating the Importance of Accessory Food Factors in Normal Dietaries", in which he demonstrated the need for vitamins in the diet. In 1921, he isolated a substance which he later proved to be a tripeptide of (Glu)glutamic acid, glycine (Gly), and cysteine (Cys). This substance was shown to be widely distributed in rapidly-multiplying plant and animal cells. In 1929, Hopkins and Christiaan Eijkman were awarded the Nobel Prize in Physiology or Medicine for their discovery that vitamins were important in order to maintain good health. Hopkins other contributions to biochemistry included discovering a method that isolated tryptophan (Trp)and identified its structure. Additionally, his work with Walter Fletcher on metabolic changes in muscle contraction and rigor mortis led to the discovery that lactic acid could accumulate from muscle contractions. Furthermore, Hopkins also discovered a specific enzyme commonly found in tissues and milk known as xanthine oxidase that catalyzes the oxidation of the purine bases xanthine and hypoxanthine to uric acid. Hopkins' discoveries served as significant contributions to understanding cell metabolism and improving biochemical research methods.
In the beginning of the 20th century, Gustav Embden, Otto Meyerhof and Jakub Karol Parnas discovered the Embden-Meyerhof-Parnas pathway (EMP Pathway), the most common glycolysis pathway. In 1925, Theodore Svedberg invented the ultracentrifuge, which he used to research colloids and proteins. In 1926, James B. Sumner crystallized Urease, an enzyme that catalyzes the conversion of urea into carbon dioxide and ammonia. He was later awarded the Nobel Prize in 1946 for his contribution. All of these developments have contributed to furthering biochemical research.
Another significant historic event in biochemistry was the discovery of genes and their role in the transfer of information in the cell. This branch of biochemistry is often referred to as molecular biology. In the 1950s, James D. Watson, Francis Crick, Rosalind Franklin, and Maurice Wilkins were revolutionaries in solving [[Structural Biochemistry/Nucleic Acid/DNA|]DNA] structure and suggesting its relationship with the genetic transfer of information. In 1958, George Beadle and Edward Tatum received the Nobel Prize for work in fungi, showing that one gene produces one enzyme. Marshall W. Nirenberg is best known for his contributions to deciphering the [code]. His collaboration with Johann Matthaei led to the demonstration that messenger RNA (mRNA) was required for protein synthesis and that synthetic mRNA preparations can be used to decipher various aspects of the genetic code. In 1964, Nirenberg announced that he and Philip Leder had developed a tRNA binding technique for determining the [code]on pieces of tRNA. As a result, three-base codons were assigned to amino acids[[|]], and as a result, 50 codons were identified. These results were confirmed by Gobind Khorana's experiments, and thus the translation of the genetic code was completed. In 1968, Nirenberg (along with Khorana and Robert Holley) received the Nobel Prize in Physiology or Medicine for interpreting the genetic code, and determining its function in protein synthesis based on the assignment of the three-base codons. In 1988, Colin Pitchfork was the first person convicted of murder with DNA evidence, which led to growth of forensic science. More recently, Andrew Z. Fire and Craig C. Mello received the 2006 Nobel Prize for discovering the role of RNA interference (RNAi), in the silencing of gene expression. Using RNAi scientists can determine which genes are used in the process of tissue regeneration.
Today, there are three main types of biochemistry: Plant biochemistry involves the study of the biochemistry of autotrophic organisms such as photosynthesis and other plant specific biochemical processes; general biochemistry encompasses both plant and animal biochemistry; Human/medical/medicinal biochemistry focuses on the biochemistry of humans and medical illnesses.