Protein: Difference between revisions

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Proteins were recognized as a distinct class of biological molecules in the eighteenth century by [[Antoine François, comte de Fourcroy|Antoine Fourcroy]] and others, distinguished by the molecules' ability to [[coagulate]] or [[flocculation|flocculate]] under treatments with heat or acid. Noted examples at the time included [[albumin]] from [[egg white]]s, blood [[serum albumin]], [[fibrin]], and wheat [[gluten]].

Proteins were first described by the Dutch chemist [[Gerardus Johannes Mulder]] and named by the Swedish chemist [[Jöns Jacob Berzelius]] in 1838. Mulder carried out [[elemental analysis]] of common proteins and found that nearly all proteins had the same [[empirical formula]], C400H620N100O120P1S1. He came to the erroneous conclusion that they might be composed of a single type of (very large) molecule. The term "protein" to describe these molecules was proposed by Mulder's associate Berzelius; protein is derived from the [[Greek language|Greek]] word {{lang|el|πρώτειος|italic=no}} ({{transliteration|el|proteios|italic=yes}}), meaning "primary", "in the lead", or "standing in front", + ''[[wikt:-in#Suffix|-in]]''. Mulder went on to identify the products of protein degradation such as the [[amino acid]] [[leucine]] for which he found a (nearly correct) molecular weight of 131 [[atomic mass unit|Da]].~~<ref name=Perrett2007/>~~ Prior to "protein", other names were used, like "albumins" or "albuminous materials" (''Eiweisskörper'', in German).

Proteins were first described by the Dutch chemist [[Gerardus Johannes Mulder]] and named by the Swedish chemist [[Jöns Jacob Berzelius]] in 1838. Mulder carried out [[elemental analysis]] of common proteins and found that nearly all proteins had the same [[empirical formula]], C400H620N100O120P1S1. He came to the erroneous conclusion that they might be composed of a single type of (very large) molecule. The term "protein" to describe these molecules was proposed by Mulder's associate Berzelius; protein is derived from the [[Greek language|Greek]] word {{lang|el|πρώτειος|italic=no}} ({{transliteration|el|proteios|italic=yes}}), meaning "primary", "in the lead", or "standing in front", + ''[[wikt:-in#Suffix|-in]]''. Mulder went on to identify the products of protein degradation such as the [[amino acid]] [[leucine]] for which he found a (nearly correct) molecular weight of 131 [[atomic mass unit|Da]]. Prior to "protein", other names were used, like "albumins" or "albuminous materials" (''Eiweisskörper'', in German).

Early nutritional scientists such as the German [[Carl von Voit]] believed that protein was the most important nutrient for maintaining the structure of the body, because it was generally believed that "flesh makes flesh." [[Karl Heinrich Ritthausen]] extended known protein forms with the identification of [[glutamic acid]]. At the [[Connecticut Agricultural Experiment Station]] a detailed review of the vegetable proteins was compiled by [[Thomas Burr Osborne (chemist)|Thomas Burr Osborne]]. Working with [[Lafayette Mendel]] and applying [[Liebig's law of the minimum]] in feeding [[laboratory rat]]s, the nutritionally [[essential amino acid]]s were established. The work was continued and communicated by [[William Cumming Rose]]. The understanding of proteins as [[polypeptide]]s came through the work of [[Franz Hofmeister]] and [[Hermann Emil Fischer]] in 1902. The central role of proteins as [[enzyme]]s in living organisms was not fully appreciated until 1926, when [[James B. Sumner]] showed that the enzyme [[urease]] was in fact a protein.

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 Proteins were recognized as a distinct class of biological molecules in the eighteenth century by [[Antoine François, comte de Fourcroy|Antoine Fourcroy]] and others, distinguished by the molecules' ability to [[coagulate]] or [[flocculation|flocculate]] under treatments with heat or acid. Noted examples at the time included [[albumin]] from [[egg white]]s, blood [[serum albumin]], [[fibrin]], and wheat [[gluten]].
-Proteins were first described by the Dutch chemist [[Gerardus Johannes Mulder]] and named by the Swedish chemist [[Jöns Jacob Berzelius]] in 1838. Mulder carried out [[elemental analysis]] of common proteins and found that nearly all proteins had the same [[empirical formula]], C<sub>400</sub>H<sub>620</sub>N<sub>100</sub>O<sub>120</sub>P<sub>1</sub>S<sub>1</sub>. He came to the erroneous conclusion that they might be composed of a single type of (very large) molecule. The term "protein" to describe these molecules was proposed by Mulder's associate Berzelius; protein is derived from the [[Greek language|Greek]] word {{lang|el|πρώτειος|italic=no}} ({{transliteration|el|proteios|italic=yes}}), meaning "primary", "in the lead", or "standing in front", + ''[[wikt:-in#Suffix|-in]]''. Mulder went on to identify the products of protein degradation such as the [[amino acid]] [[leucine]] for which he found a (nearly correct) molecular weight of 131 [[atomic mass unit|Da]].<ref name=Perrett2007/> Prior to "protein", other names were used, like "albumins" or "albuminous materials" (''Eiweisskörper'', in German).
+Proteins were first described by the Dutch chemist [[Gerardus Johannes Mulder]] and named by the Swedish chemist [[Jöns Jacob Berzelius]] in 1838. Mulder carried out [[elemental analysis]] of common proteins and found that nearly all proteins had the same [[empirical formula]], C<sub>400</sub>H<sub>620</sub>N<sub>100</sub>O<sub>120</sub>P<sub>1</sub>S<sub>1</sub>. He came to the erroneous conclusion that they might be composed of a single type of (very large) molecule. The term "protein" to describe these molecules was proposed by Mulder's associate Berzelius; protein is derived from the [[Greek language|Greek]] word {{lang|el|πρώτειος|italic=no}} ({{transliteration|el|proteios|italic=yes}}), meaning "primary", "in the lead", or "standing in front", + ''[[wikt:-in#Suffix|-in]]''. Mulder went on to identify the products of protein degradation such as the [[amino acid]] [[leucine]] for which he found a (nearly correct) molecular weight of 131 [[atomic mass unit|Da]]. Prior to "protein", other names were used, like "albumins" or "albuminous materials" (''Eiweisskörper'', in German).
 Early nutritional scientists such as the German [[Carl von Voit]] believed that protein was the most important nutrient for maintaining the structure of the body, because it was generally believed that "flesh makes flesh." [[Karl Heinrich Ritthausen]] extended known protein forms with the identification of [[glutamic acid]]. At the [[Connecticut Agricultural Experiment Station]] a detailed review of the vegetable proteins was compiled by [[Thomas Burr Osborne (chemist)|Thomas Burr Osborne]]. Working with [[Lafayette Mendel]] and applying [[Liebig's law of the minimum]] in feeding [[laboratory rat]]s, the nutritionally [[essential amino acid]]s were established. The work was continued and communicated by [[William Cumming Rose]]. The understanding of proteins as [[polypeptide]]s came through the work of [[Franz Hofmeister]] and [[Hermann Emil Fischer]] in 1902. The central role of proteins as [[enzyme]]s in living organisms was not fully appreciated until 1926, when [[James B. Sumner]] showed that the enzyme [[urease]] was in fact a protein.