Development Of Energy Transfer Research Articles

ЭНЕРГОПЕРЕХОД И ЦИФРОВИЗАЦИЯ ЭКОНОМИКИ: СОВРЕМЕННАЯ ПОВЕСТКА И КОНКУРЕНЦИЯ СТРАН

Aspects of the study of the relationship between the development of digital technologies and their increasing impact on the environment and the assessment of the elimination of contradictions in the development of energy transfer in the digital economy on the basis of state regulation are considered. The conclusion is made about the spread of “green” protectionism as a tool for ensuring information, environmental and energy security of countries with increasing energy consumption.

Development of the photosystem II unit in plastids of bean leaves greened in periodic light

The photosystem II (PS II) unit formation and development, as monitored by the kinetics of the fluorescence induction, was studied in greening protochloroplasts isolated from etiolated bean leaves exposed to periodic light-dark cycles (LDC). It was found that: (i) The protochloroplasts show the well-known biphasic induction. The F MAX F O ratio increases with increasing exposure to LDC, and values almost twice as high as those of mature chloroplasts are reached. The fluorescence yield increases still more by the addition of NH 2OH. (ii) The ratio ( F MAX -F O ) F MAX , representing the yield of primary photochemistry, reaches values much higher than those of mature chloroplasts. (iii) The rate of fluorescence rise, in the presence or absence of 3-(3,4-dichlorophenyl)-1,1-di-methylurea (DCMU), is at least seven times slower than that of mature chloroplasts, and it remains constant during exposure to LDC. (iv) The shape of the fluorescence kinetics is exponential early during exposure to LDC but later it becomes sigmoidal, indicating the development of energy transfer between PS II units, (v) Dark incubation after a number of LDC increases the F MAX F O ratio without changing the rate of the fluorescence rise, (vi) Transfer of the plants from LDC to continuous illumination induces a decrease in the F MAX F O ratio and an increase in the rate of the fluorescence rise. The results indicate that initially small PS II units are formed, which contain mainly the reaction center with a few chlorophyll a molecules closely packed around it. At the same time H 2O-splitting enzymes are synthesized which, however, are light activated. These small units are very efficient for photochemistry. As the number of small units increases, aggregates are formed, which seem to have the reaction centers very close to each other. The aggregation of the units is controlled by the structural development and organization of the membrane and not by the concentration and type of chlorophyll. The excess chlorophyll formed after further exposure to continuous illumination is inserted into preexisting units, thus increasing their size and making them more efficient in absorbing the incident light.

Photosynthetic membrane development in Rhodopseudomonas spheroides: Incorporation of bacteriochlorophyll and development of energy transfer and photochemical activity

1. 1. Bleached cells of Rhodopseudomonas spheroides, obtained by aerobic growth in the light, rapidly synthesize bacteriochlororphyll and carotenoids when transferred to 4% oxygen in the dark. Fluorescence excitation spectra of whole cells during the initial stages of pigment synthesis indicate that the major fraction of the newly synthesized bacteriochlorophyll is immediately incorporated into photosynthetic membranes and can receive excitation energy transferred from the carotenoids. Activity of the photosynthetic reaction centers, as measured by the effect of dithionite addition on the fluorescence of the incorporated bacteriochlorophyll, develops simultaneously with pigment incorporation. 2. 2. Fluorescence excitation and emission spectra also indicate the presence of an unbound form of bacteriochlorophyll in vivo as well as a form of bacteriopheophytin. We suggest that this free bacteriochlorophyll is in a “pool” from which it is incorporated into the membranes and that the bacteriopheophytin (or bacteriopheophorbide) is formed by the degradation of the free and thus unprotected form of the bacteriochlorophyll.