Membrane Operational Impedance Spectra in Chara corallina Estimated by Laplace Transforms Analysis.
نویسندگان
چکیده
The membrane operational impedance spectrum of Chara corallina Klein ex Willd. (R. Brown) cells is investigated using Laplace transform analysis. The spectrum changes with both amplitude and sign of the electrical stimulation when time- and voltage-dependent K(+) channels contribute to the membrane conductance. We compare the advantages and disadvantage of this technique for studying membrane impedance with those of the alternating current method and the white noise method.
منابع مشابه
Involvement of membrane potential in alkaline band formation by internodal cells of Chara corallina.
Internodal cells of Chara corallina form alkaline bands on their surface upon illumination via photosynthesis. In the present study, the effect of KCl on alkaline band formation was analyzed. When the extracellular KCl concentration was increased, alkaline band formation was extensively inhibited. Electrophysiological analysis unequivocally showed the need for inner negative membrane potential ...
متن کاملPlasmalemma Voltage Noise in Chara corallina.
Voltage noise analysis is applied to plasmalemma ion transport in Chara corallina. There is a component in the noise power spectrum that is probably associated with current fluctuations within passive transport channels, and another component that may be associated either with fluctuations in the number of open channels, or with active transport. The data allow the calculation of time constants...
متن کاملVoltage-Dependent K-Channel in Protoplasmic Droplets of Chara corallina: A Single Channel Patch Clamp Study.
Passive transport of potassium through the plasma membrane of a protoplasmic droplet isolated from large internodal cells of Chara corallina Klein ex Willd., em, R.D.W. has been investigated using the patchclamp technique. When the membrane is hyperpolarized the conductance of a single K(+)-channel is of the order of magnitude of 100 picoSiemens and is reduced by tetraethylammonium chloride. It...
متن کاملSimultaneous Measurements of Cytoplasmic K Concentration and the Plasma Membrane Electrical Parameters in Single Membrane Samples of Chara corallina.
The electrophysiological properties of cytoplasm-rich fragments (single membrane samples) prepared from internodal cells of Chara corallina were explored in conjunction with K(+)-sensitive microelectrode and current-voltage (I-V) measurements. This system eliminated the problem of the inaccessible cytoplasmic layer, while preserving many of the electrical characteristics of the intact cells. In...
متن کاملCalcium deprivation disrupts enlargement of Chara corallina cells: further evidence for the calcium pectate cycle
Pectin is a normal constituent of cell walls of green plants. When supplied externally to live cells or walls isolated from the large-celled green alga Chara corallina, pectin removes calcium from load-bearing cross-links in the wall, loosening the structure and allowing it to deform more rapidly under the action of turgor pressure. New Ca(2+) enters the vacated positions in the wall and the ex...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Plant physiology
دوره 81 3 شماره
صفحات -
تاریخ انتشار 1986