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Net H(+) influx inNitella clavata
R K Rent1, R A Johnson, C E Barr
1Department of Biological Sciences, State University College, 14420, Brockport, N.Y..
The Journal of Membrane Biology
|November 2, 2013
Summary
Giant algal cells (Nitella clavata) show high membrane permeability to hydrogen ions (H+). Studies indicate minimal internal pH change and significant external H+ adsorption by the membrane.
Area of Science:
- Plant Physiology
- Cell Biology
- Biophysics
Background:
- The plasma membrane's role in ion transport is crucial for cellular homeostasis.
- Understanding hydrogen ion (H+) permeability is key to cellular pH regulation.
Purpose of the Study:
- To quantify net hydrogen ion (H+) influx in Nitella clavata.
- To investigate the permeability of the Nitella membrane to H+.
- To explore the membrane's capacity for H+ adsorption.
Main Methods:
- Net H+ influx measurements using giant internodal cells of Nitella clavata.
- Exposure of cells to low pH solutions (4.5-4.7).
- Monitoring pH changes and acid addition required to maintain low pH.
Main Results:
- Measurements align with Kitasato's (1968) findings, supporting high H+ permeability.
- Internal pH remained largely stable despite external acidic conditions.
- Evidence suggests significant H+ adsorption capacity on the external membrane surface.
Conclusions:
- The Nitella membrane exhibits substantial permeability to H+.
- The cell membrane possesses a notable capacity for adsorbing H+ externally.
- Internal pH is effectively buffered, indicating robust regulatory mechanisms.
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