THE ELECTRICAL CONDUCTIVITY OF PURE PROTOPLASM

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S C Brooks1

  • 1Division of Pharmacology, Hygienic Laboratory, United States Public Health Service, Washington, D. C.

The Journal of General Physiology
|October 30, 2009
PubMed

Insights

The electrical conductivity of slime mold protoplasm is similar to a dilute salt solution. Increased conductivity in seawater suggests protoplasm is permeable to electrolytes.

Area of Science:

  • Biophysics
  • Cell Biology

Background:

  • Slime molds, like Brefeldia maxima, are valuable models for studying protoplasmic properties due to their composition.
  • Understanding the electrical properties of protoplasm is crucial for elucidating cellular transport mechanisms.

Purpose of the Study:

  • To measure the electrical conductivity of Brefeldia maxima plasmodium.
  • To investigate the relationship between protoplasmic conductivity and its surrounding environment.

Main Methods:

  • Electrical conductivity measurements of the slime mold plasmodium.
  • Comparison of conductivity with standard saline solutions and the external medium.

Main Results:

  • The electrical conductivity of Brefeldia maxima plasmodium approximates that of a 0.00145 N NaCl solution under normal conditions.
  • Conductivity significantly increased when the slime mold was bathed in 1% seawater, exceeding that of the external fluid.
  • The slime mold's conductivity was approximately 2.8 times higher than the liquid it developed in.

Conclusions:

  • Preliminary findings support the hypothesis that slime mold protoplasm is permeable to electrolytes.
  • The results suggest that protoplasm maintains an electrolyte equilibrium with its environment.

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