A text-book of physiological chemistry / by Olof Hammarsten ; authorized translation from the author's enl. and rev. 5th German ed. by John A. Mandel.

  • Olof Hammarsten
Date:
1904
Catalogue details

Licence: Public Domain Mark

Credit: A text-book of physiological chemistry / by Olof Hammarsten ; authorized translation from the author's enl. and rev. 5th 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.

    27/746 page 11
    with the life of the yeast, The inversion of cane-sugar is, on the contrary, an enzymotic process caused by one of the bodies or mixture of bodies formed by the living ferment, which can be severed from this ferment, and still remain active even after the death of the latter. Consequently fer- ments and enzymes are capable of manifesting a different behavior towards certain chemical reagents. Thus there exist a number of substances, among which we may mention[arsenious acid, phenol, toluene, salicylic acid, boracic acid, sodium fluoride, chloroform, ether]] and others, which in certain concentration kill ferments, but which do not noticeably impair the action of the enzymes. The above view as to the difference between ferments and enzymes has lately been essentially shaken by the researches of E. Buchner ! and his pupils. He has been able to obtain from beer-yeast, by grinding and strong pressure, a cell fluid rich in proteid which when introduced into a solution of a fermentable sugar caused a violent fermentation. The objections raised from several sides that the fluid expressed still contained dissolved living cell substance has been so successfully answered by Btjch- ner and his collaborators, that there is at present no question but that alcoholic fermentation is caused by a special enzyme called zymase which is formed in the yeas^-cell. As from the yeast-cell so also from other lower organisms, indeed from the lactic-acid bacilli and beer-vinegar bacteria., we have recently been able to isolate enzymes (E. Buchxer and Meisexheimer, Herzog '-') which produce the specific fermentative action of the mother organism. We have therefore now no foundation for a sharp differentiation between the organized ferments and the enzymes. Many enzymes are secreted by the cells and are therefore called secre- tion enzymes. These do not seem to be secreted as such, but more likely occur as precursors of the enzymes, the zymogens, in the cells. These zymogens are then transformed by special influence into the enzymes Besides these extracellular enzymes we also find others which are active within the cells, the intracellular enzymes. To this group belongs a large number of enzymes, among which are those proteolytic enzymes first observed by Salkowski and his pupils, which produce post-mortem self- digestion of different organs^ which he called autodigestion. Jacop.y has recently further studied this autodigestion and has called it autolysis. We 1 E. Buchner, Ber. d. deutsch. chem. Gesellsch., 30 and 31; E. Buchner and Rapp, ibid., 31, 32, 34; H. Buchner, Sitzungsber. d. Gesellsch. f. Morphol. u. Physiol, in Miinchen, 13, 1897, part 1, which also contains the discussion on this topic. See also Stavenhagen, Ber. d. deutsch. Chem. Gesellsch., 30; Albert and Buchner, ibid., 33; Buchner, ibid., 33; Albert, ibid., 33; Albert, Buchner, and Rapp, ibid., 3.>; in regard to the opposed views see Macfadyen, Morris and Rowland, QrieL, 33; Wroblewski, Centralbl. f. Physiol., 13, and Journ. f. prakt. Chem. (N. F.), 04. 2 E. Buchner and Meisenheimer, Ber. d. d. chem. Gesellsch., 30; Herzog, Zeitschr. f. physiol. Chem., 37.
    digitised image 1
    digitised image 2
    digitised image 3