[Participation of its reaction center in the electrochemical reduction of ferredoxin]. / Ob uchastii v élektrokhimicheskom vosstanovlenii ferredoksina ego reaktsionnogo tsentra.

In the experiments with reaction center modification of ferredoxin its participation in reduction has been shown. Polarographic characteristics of ferredoxin and apoferredoxin have been compared. While removing iron and labile sulphur from ferredoxin reaction center the reduction wave of Fe-S bonds with E 1/2 = -0.33 V (N. H. E.) transforms into the reduction wave of S-S bonds with E 1/2 = -0,39 V at pH = 7.

[Study of the kinetics of chlorophyll photosensitized dye reduction by photopolarography]. / Izuchenie kinetiki fotosensibilizirovannogo khlorofillom vosstanovleniia krasitelei metodom fotopoliarografii.

It has been shown by photopolarographic method that under stationary illumination chlorophyll-photosensitized reduction of dyes with ascorbic acid proceeds according to the first kinetic order. Rate constants of photoreduction of vitamin K3, methelene red, safranin-T and methylviologen were found in the course of sensitization which proceeded by oxidative and reduction mechanisms. Similarity of kinetics at both sensitization mechanisms was shown. Results obtained by polarographic and spectroscopic methods were compared.

[Oxidation-reduction potentials of chlorophyll pigments in photosynthesizing organisms on different levels of evolutionary development]. / Okislitel'no-vosstanovitel'nye potentsialy khlorofillovykh pigmentov fotosinteziruiushchikh organizmov, stoiashchikh na raznykh urovniakh évoliutsionnogo razvitiia

According to polarographically measured EOred of bacteriochlorophyll "a", chlorobium chlorophyll "660", "b" and "a" chlorophylls (-0.67 V, -0.73 V, -0.79 V, -0.86 V-n.h.e.) and literature data about Eoox of these pigments (+/-0.62 V, + 0.62 V, + 0.78 V, +0.77 V correspondingly) it has been shown that chemical energy stored in the singular photochemical set is increased in the evolution of the photosynthetic apparatus. It has apparently resulted in the possibility of evolutionary approach to utilization of more inert and more accessible (water) electron donors and favoured further development of photosynthesizing organisms.

[Ferredoxin reduction by polarographic methods]. / O vosstanovlenii ferredoksina poliarograficheskimi metodami

The reduction of iron-sulphur protein of the higher plant ferrodoxin has been studied by polarographical methods. Ferredoxin initiates a reversible wave with E1/2=--0,61 v (N. C. E.) at pH 7. Protein absorption greatly influences the electrochemical reduction. The protons have been shown to take part in the electrode reaction. The potentiometrically obtained data about the difference between E1/2 and E0=--0.70 v and its causative factors are discussed. As a result of the experiments with modification of ferredoxin active centre it has been concluded that the active centre participates in the polarographical reduction.