Researches on the nature of enzyme-action. I, On the causes of the rise in electrical conductivity under the action of trypsin / by W.M. Bayliss.

William Bayliss

Date:: [1907?]

Credit: Researches on the nature of enzyme-action. I, On the causes of the rise in electrical conductivity under the action of trypsin / by W.M. Bayliss. Source: Wellcome Collection.

Cover
Title Page
Cover

3/32 page 223

CHANGES IN VISCOSITY. It is easy to show that the first cause, although it. may assist to a slight degree, is altogether inadequate to explain the whole of the effect produced by trypsin. In the first place the time course of the change of internal friction is very different from that of the electrical conductivity. In the curves given in my former paper (p. 15 of the reprint) it will be seen that the internal friction diminishes much faster than the conductivity increases, and also that the former change has come to an end while the con- ductivity is still increasing. Owing to the extremely rapid change in the internal friction under the action of trypsin at 38° I have repeated the experiment at a temperature of 19°°3. Exp. 40 c.c. of a 5°, solution of caseinogen in ammonia, acid to phenol-phthalein, alkaline to litmus, warmed in flask in thermostat at 19°-3. 5 c.c. of 2°/,) filtered watery extract of ‘‘Rhenania”’ pancreatin, also previously warmed, added, shaken, and portions immediately poured into a conductivity vessel and an Ostwald viscosimeter already immersed in the thermostat. Resistance and internal friction taken at intervals as follows: Resistance values are given instead of specific conductivity since the changes of resistance and internal friction are in the same direction and therefore easier to compare. Time in Rate of flow through . Resistance minutes capillary in seconds in ohms 0 (183) * (333)* 4 — 325°5 8 160 — 12 — 308°2 16 137 — 20 mo 298°4 30 115 286-1 45 105 273°1 74 95 254°6. 81 92 a 131 85 230°0 180 82 216°5 246 79 204°9 342 oe 195:°0 466 77 187°4 541 76 184°9 “a 74 180°1 * Calculated. The change in viscosity at first is too rapid to admit of accurate measurement directly. The curves of Fig. 1 are drawn from these values. The numbers on the left refer to the viscosity curve and give the values of its ordinates in seconds; those on the right refer to the electrical resistance curve and 15—2

Researches on the nature of enzyme-action. I, On the causes of the rise in electrical conductivity under the action of trypsin / by W.M. Bayliss.

Licence and re-use

Contents