Energization
Mostrando 13-24 de 88 artigos, teses e dissertações.
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13. Energization of Transport Processes in Plants. Roles of the Plasma Membrane H+-ATPase1
American Society of Plant Biologists.
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14. The Physiological Relevance of Na+-Coupled K+-Transport.
Plant roots utilize at least two distinct pathways with high and low affinities to accumulate K+. The system for high-affinity K+ uptake, which takes place against the electrochemical K+ gradient, requires direct energization. Energization of K+ uptake via Na+ coupling has been observed in algae and was recently proposed as a mechanism for K+ uptake in wheat
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15. Respiration-Linked Proton Transport, Changes in External pH, and Membrane Energization in Cells of Escherichia coli
The kinetics of respiration-dependent proton efflux and membrane energization have been studied in intact cells of logarithmic-phase Escherichia coli. Parallel measurements of the rate and extent of proton efflux into the external medium (half-time, about 10 s; ratio of H+ to O, about 0.5) and the oxidation of E. coli cytochrome b (half-time, ≤1 s; about 6
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16. Affinity of intact Escherichia coli for hydrophobic membrane probes is a function of the physiological state of the cells.
The fluorescence parameters of several common membrane probes in the presence of whole E. coli have been examined. The probes included electrically neutral lipophilic molecules N-phenyl-1-naphthylamine, pyrene, and 1,6-diphenyl-1,3,5-hexatriene as well as the negatively charged molecule 8-anilino-1-naphthalene sulfonate. It is demonstrated in each case that
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17. Demonstration of a transitory tight binding of ATP and of committed Pi and ADP during ATP synthesis by chloroplasts
Rapid mixing, quenching, and filtration experiments with chloroplast thylakoid membranes, with energization by acid-base transition, demonstrate that an ATP tightly bound to the isolated membranes is a transient intermediate in the catalytic sequence for ATP synthesis. The experiments also show that most of the Pi and ADP bound at a catalytic site is committ
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18. Control of phosphoenolpyruvate-dependent phosphotransferase-mediated sugar transport in Escherichia coli by energization of the cell membrane.
The phosphoenolpyruvate-dependent phosphotransferase-mediated sugar transport in Escherichia coli is inhibited by the energized of the membrane. This was shown in intact cells as well as in membrane vesicles. Relaxation of the proton gradient by uncouplers stimulated the uptake of sugars via the phosphotransferase system in aerobically cultured cells. No suc
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19. Escherichia coli mutants defective in the uncH gene.
Plasmids carrying cloned segments of the unc operon of Escherichia coli have been used in genetic complementation analyses to identify three independent mutants defective in the uncH gene, which codes for the delta subunit of the ATP synthetase. Mutations in other unc genes have also been mapped by this technique. ATPase activity was present in extracts of t
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20. Energization of the Sugar Transport Mechanism in the Plasmalemma of Isolated Mesophyll Protoplasts 1
The mechanism of 3-O-methyl-d-glucose transport through the plasmalemma has been investigated in protoplasts isolated from the mesophyll of Pisum sativum L. var. Dan.
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21. Patterns of electrochemical proton gradient formation by membrane vesicles from an obligately acidophilic bacterium.
Isolated membrane vesicles from the obligately acidophilic bacterium Bacillus acidocaldarius generated an electrochemical gradient of protons (delta mu- H+) upon energization with ascorbate-phenazine methosulfate at pH 6.0 or 3.0. At pH 6.0, there was little or no transmembrane pH gradient (delta pH), but a transmembrane electrical potential (delta psi) of c
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22. Continuous Equilibration of Phosphatidylcholine and Its Precursors between Endoplasmic Reticulum and Mitochondria in Yeast
In Saccharomyces cerevisiae phosphatidylcholine (PC) is synthesized in the ER and transported to mitochondria via an unknown mechanism. The transport of PC synthesized by the triple methylation of phosphatidylethanolamine was investigated by pulsing yeast spheroplasts with l-[methyl-3H]methionine, followed by a chase with unlabeled methionine and subcel
The American Society for Cell Biology.
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23. Evidence for the involvement of coupling factor B in the H+ channel of the mitochondrial H+-ATPase.
Membrane energization by ATP has been measured in vesicles containing purified bovine heart mitochondrial H+-ATPase (ATP synthase) with the voltage-sensitive dye oxonol VI. The dithiol chelator, Cd2+, and the thiol oxidant, copper o-phenanthroline, produced discharge of the membrane potential when added at the steady state and inhibited its establishment whe
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24. The Mrp Na+/H+ Antiporter Increases the Activity of the Malate:Quinone Oxidoreductase of an Escherichia coli Respiratory Mutant
Mrp catalyzes secondary Na+/H+ antiport and was hypothesized to have an additional primary energization mode. Mrp-dependent complementation of nonfermentative growth of an Escherichia coli respiratory mutant supported this hypothesis but is shown here to be related to increased expression of host malate:quinone oxidoreductase, not to catalytic activity of Mr
American Society for Microbiology.