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Published on: September 26, 2017
TRANSVERSE ELECTRIC IMPEDANCE OF NITELLA
1Department of Physiology, College of Physicians and Surgeons, Columbia University, New York.
The Journal of General Physiology
|October 30, 2009
Summary
Electrical impedance measurements on Nitella cells reveal the cellulose wall
Area of Science:
- Plant cell electrophysiology
- Biophysics of plant cells
Background:
- Understanding the electrical properties of plant cells is crucial for various biological processes.
- Nitella cells are a model organism for studying cellular electrophysiology.
Purpose of the Study:
- To investigate the electrical impedance of single Nitella cells across a wide frequency range.
- To determine the electrical properties of the cell wall, membrane, and internal sap.
Main Methods:
- Alternating current (AC) impedance spectroscopy was applied to single Nitella cells.
- Measurements were conducted with current flow perpendicular to the cell axis.
- Electrolytes of varying concentrations were circulated around the cells.
Main Results:
- The cellulose cell wall exhibits a specific resistance of approximately 1000 ohm cm, independent of the external medium.
- The cell membrane shows negligible conductivity, with a capacitance of 0.94 microfarads/cm² and a phase angle of 80 degrees.
- Extracted Nitella sap has a specific resistance of 58 ohm cm, independent of the medium.
Conclusions:
- The cellulose wall significantly influences electrical measurements in Nitella cells.
- The cell membrane's electrical properties were quantified.
- Chloroplasts may possess impedance characteristics analogous to those of the entire cell.
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