Discoveries

X-rays

DEFINITION An X-ray is an invisible, highly penetrating electromagnetic radiation of much shorter wavelength (higher frequency) than visible light. The wavelength range for X-rays is from about 10⁻⁸ m to about 10⁻¹¹ m; the corresponding frequency range is from about 3 × 10¹⁶ Hz to about 3 × 10¹⁹ Hz. Photographs made with X-rays are …

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Anion

DEFINITION An anion is a monoatomic or polyatomic species having one or more elementary charges of the electron[1]. DISCOVERY The English scientist Michael Faraday discovered[2] the anion in 1834 while analysing the electrochemical properties of electrolytic solutions. In an effort to create an electrochemical nomenclature, he says in his 1834 publication, “Finally, I require a …

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Fibrinogen

DEFINITION Fibrinogen is a protein in the blood plasma that is essential for the coagulation of blood and is converted to fibrin by the action of thrombin in the presence of ionised calcium[1]. It is also called “coagulation factor I”. DISCOVERY The Swedish physiologist Olof Hammarsten discovered[2] fibrinogen in 1877 after researching what substances in …

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Cation

DEFINITION A cation is a monoatomic or polyatomic species having one or more elementary charges of the proton[1]. DISCOVERY The English scientist Michael Faraday discovered[2] cations in 1834 while analysing the electrochemical properties of electrolytic solutions. In an effort to create an electrochemical nomenclature, he says in his 1834 publication, “Finally, I require a term …

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Fibrin

DEFINITION Fibrin is an elastic, insoluble, whitish protein produced by the action of thrombin on fibrinogen and forming an interlacing fibrous network in the coagulation of blood[1]. DISCOVERY The Italian biologist Marcello Malpighi discovered[2] fibrin in 1666 while examining washed blood clots under a microscope. In his publication[2] he describes the washed (to the point …

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Thrombocytus

DEFINITION The thrombocytus (more commonly known as the platelet/thrombocyte) is a minute, non-nucleated, disc-like cytoplasmic body found in the blood plasma of mammals that is derived from a megakaryocyte and functions to promote blood clotting[1]. DISCOVERY The German anatomist  Max Johann Sigismund Schultze discovered[2] platelets in 1865 while examining blood under a microscope. In his …

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Glutamic acid

DEFINITION Glutamic acid is a nonessential amino acid with the chemical formula C5H9NO4. It is used principally in the biosynthesis of proteins and an important metabolic intermediate[1]. DISCOVERY The German chemist Karl Heinrich Leopold Ritthausen discovered[2] glutamic acid in 1866 while experimenting on wheat gluten. In his publication[2], he explains the method by which he …

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Tyrosine

DEFINITION Tyrosine is a nonessential amino acid with the chemical formula C9H11NO3. It is produced in the body from phenylalanine and is a precursor of melanin and of several neurotransmitters and hormones, such as epinephrine and thyroxine[1]. DISCOVERY The German chemist Justus Freiherr von Liebig discovered[2] tyrosine in 1846 while experimenting with cheese. In his …

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Histidine

DEFINITION Histidine is a naturally occuring essential amino acid with the chemical formula C6H9N3O2. It is necessary for tissue growth and repair[1]. DISCOVERY The German biochemist Ludwig Karl Martin Leonhard Albrecht Kossel discovered[2] histidine in 1896 while studying sturine (a protamine in the spermatozoa of sturgeon). Here is how he isolated histidine from it: He …

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Ruthenium

DEFINITION Ruthenium is a metallic chemical element with the symbol Ru, atomic number 44 and atomic weight 101.07. It is a hard, lustrous, silver-gray metal with a close-packed hexagonal crystalline structure. Ruthenium is usually alloyed with other metals; with palladium as a hardener and with titanium to improve its corrosion resistance. It is also used …

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