A text-book of physiological chemistry / Authorized translation from the author's enl. and rev. 3rd German ed., by John A. Mandel.

  • Olof Hammarsten
Date:
1898
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Licence: Public Domain Mark

Credit: A text-book of physiological chemistry / Authorized translation from the author's enl. and rev. 3rd German ed., by John A. Mandel. Source: Wellcome Collection.

Provider: This material has been provided by the Augustus C. Long Health Sciences Library at Columbia University and Columbia University Libraries/Information Services, through the Medical Heritage Library. The original may be consulted at the the Augustus C. Long Health Sciences Library at Columbia University and Columbia University.

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    The cause of the animal oxidation is considered, by Pflugek and several other investigators, to he dependent upon the special contitution of the protoplasmic proteids. This investigator calls- the proteids outside of the organism, and also those which circulate in the blood and fluids, non-living proteids as compared to those which are converted by the activity of the living cell into living protoplasm, which he calls living proteids, It is now also con- sidered that this living proteid differs from the non-living proteid by a greater mobility of the atoms within the molecule, and it may be characterized by a greater inclination towards intra- molecular changes of position of these atoms. The reason for these greater intramolecular movements Pfluger * ascribes to the presence of cyanogen, Loew ^ to the presence of aldehydic groups, and Latham ^ attributes it to the presence of a chain of cyanalcohols in the proteid molecule. Pfluger considers these differences between ordinary proteids and living protoplasmic proteids as the cause for the oxidation processes in the animal organism. These processes show certain similarity to the oxidation of phosphorus in an atmosphere contain- ing oxygen. In this process the phosphorus is not only itself oxidized, but, as it splits the oxygen molecules and sets free oxygen atoms (active oxygen), it may cause at the same time an indirect or secondary oxidizing action upon other bodies present. In an analogous way the living protoplasmic proteid, which is not, like dead proteid, indifferent to molecular oxygen, may cause a splitting of the oxygen molecule, thus becoming itself oxidized, and at the same time setting oxygen atoms free, which may cause a secondary oxidation of other less oxidizable substances. Active oxygen may also be produced, according to 0. Nasse, by a hydroxylization of the constituents of the protoplasm with the splitting off of molecules of water. If benzaldehyde is shaken with water and air an oxidation of the benzaldehyde into benzoic acid takes place, while oxidizable substances present at the same time may also be oxidized. The simultaneous presence of potassium iodide and starch or tincture of guaiacum causes a blue coloration because the hydroxy 1 (OH) takes the place of the hydrogen in the ' Pfiuger's Arcliiv, Bd. 10. '^Loevv and Bokorny, Pfliiger's Archiv, Bd. 25, and Loew, ihiiL, Bd. 30. 3 British Medical Journal, 1886. 4 Rostocker Zeitung, 1891, No. 534.
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