The light-dependent effect of external pH on the membrane potential of Nitella
In the light the membrane potential of Nitella flexilis and Nitella axilliformis was hyperpolarized by raising the external pH above pH 5.5, at the rate of 30–40 mV /pH below pH 8. This hyperpolarization was largely reduced in the dark. The membrane potential was sensitive to the external pH of medi...
| Main Authors: | , |
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| Format: | Text |
| Language: | English |
| Published: |
Oxford University Press
1973
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| Subjects: | |
| Online Access: | http://pcp.oxfordjournals.org/cgi/content/short/14/1/147 |
| Summary: | In the light the membrane potential of Nitella flexilis and Nitella axilliformis was hyperpolarized by raising the external pH above pH 5.5, at the rate of 30–40 mV /pH below pH 8. This hyperpolarization was largely reduced in the dark. The membrane potential was sensitive to the external pH of media with a low potassium concentration, where it was relatively insensitive to potassium concentration. In media of a high concentration where it was sensitive to the potassium concentration, the membrane became insensitive to the external pH. The transition from a pH-sensitive to a pH-insensitive state occurred rather abruptly on increasing the external potassium concentration. |
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