English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

After acid-treatment of spinach (Spinacia oleracea) chloroplasts, various partial electron transport reactions are inactivated from 25 to 75%. Divalent cations in concentrations from 10 to 50 millimolar can partially restore electron transport rates. Two cation-specific sites have been found in photosystem II: one on the 3-(3,4-dichlorophenyl)-1, 1-dimethylurea-insensitive silicomolybdate pathway, which responds better to restoration by Mg(2+) than by Ca(2+) ions, the other on the forward pathway to photosystem I, located on the 2,5-dimethylbenzoquinone pathway. This site is selectively restored by Ca(2+) ions. When protonated chloroplasts are treated with N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)aziridine, a carboxyl group modifying reagent, presumed to react with glutamic and aspartic acid residues of proteins, restoration of electron transport at the Ca(2+)-selective site on the 2,5-dimethylbenzoquinone pathway is impaired, while no difference in restoration is seen at the Mg(2+) site on the 3-(3,4-dichlorophenyl)-1,1-dimethylurea-insensitive silicomolybdate pathway.Trypsin treatment of chloroplasts modifies the light-harvesting pigment-protein complex, destroys the dibromothymoquinone-insensitive 2,5-dimethyl-benzoquinone reduction, but does not interfere with the partial restoration of activity of this pathway by Ca(2+) ions, implying that the selective Ca(2+) effect on photosystem II (selective Ca(2+) site) is different from its effects as a divalent cation on the light-harvesting pigment-protein complex involved in the excitation energy distribution between the two photosystems.

A Calcium-Selective Site in Photosystem II of Spinach Chloroplasts