Search results for "ATP"
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Komunikācijas loma un novērtējums beziepakojuma iepirkšanās veicināšanā Latvijā: "Zeroveikals", "Burka" un "Turza" piemērs
2019
Maģistra darba "Komunikācijas loma un novērtējums beziepakojuma iepirkšanās veicināšanā Latvijā: "Zeroveikals", "Burka" un "Turza" piemērs" mērķis ir izpētīt beziepakojuma preču veikalu "Zeroveikals", "Burka" un 'Turza" sociālo tīklu profilu un Latvijas mediju komunikācijas vēstījumu lomu un sniegt to novērtējumu, saistot to ar pašreizējo Latvijas patērētāju attieksmi pret beziepakojuma iepirkšanos. Pētījuma mērķis tika sasniegts, pielietojot pētījuma metodes kontentanalīze, intervija un aptauja. Darba teorētiskajā daļā tika apskatītas tādas teorētiskās nostādnes kā sociāla problēma, dzīvesveids, rīcības pieľemšanas faktori, pārliecināšanas komunikācija un zīmola atpazīstamības veicināšana.…
Citrate permease gene expression inLactococcus lactissubsp.lactisstrains IL1403 and MG1363
1996
Citrate permease gene expression in the plasmid-free Lactococcus lactis strains IL1403 and MG1363 was studied. The ability to transport citrate results in diacetyl and acetoin production in IL1403 but not in MG1363. Citrate lyase, α-acetolactate decarboxylase, diacetyl and acetoin reductase were detected in IL1403. These data show that L. lactis ssp. lactis strain IL1403 is a citrate permease mutant of the biovar. diacetylactis. Immunological analysis revealed the α-and β-subunits of citrate lyase not only in IL1403 but also in MG1363 where no citrate lyase activity was found.
Citrate lyases of lactic acid bacteria
1998
Citrate Iyase is a key enzyme of the citrate metabolism which is involved in flavor and texture of many fermented milk products. Citrate Iyase which catalyses the cleavage of citrate into oxaloacetate and acetate is a multienzyme complex composed of three proteins: an acyl carrier protein (ACP); a citrate, acetate-ACP transferase; and a citryl-S-ACP Iyase. The citrate Iyase is active only when the thioester residue of the prosthetic group bound to ACP is acetylated. In the presence of citrate, the transferase mediates the formation of citryl-S-acyl carrier protein by acyl exchange and liberation of acetate. Then the Iyase subunit cleaves the citryl-S-ACP with libe- ration of oxaloacetate an…
Generation of a proton potential by succinate dehydrogenase of Bacillus subtilis functioning as a fumarate reductase
2001
The membrane fraction of Bacillus subtilis catalyzes the reduction of fumarate to succinate by NADH. The activity is inhibited by low concentrations of 2-(heptyl)-4-hydroxyquinoline-N-oxide (HOQNO), an inhibitor of succinate: quinone reductase. In sdh or aro mutant strains, which lack succinate dehydrogenase or menaquinone, respectively, the activity of fumarate reduction by NADH was missing. In resting cells fumarate reduction required glycerol or glucose as the electron donor, which presumably supply NADH for fumarate reduction. Thus in the bacteria, fumarate reduction by NADH is catalyzed by an electron transport chain consisting of NADH dehydrogenase (NADH:menaquinone reductase), menaqu…
The lipid composition, fluidity, and Mg2+-ATPase activity of rice (Oryza sativa L. cv. Bahia) shoot plasma membranes: effects of ABA and GA3
1992
Six-day-old rice plants (Oryza sativa L., cv Bahia) were grown for 5 days more in nutrient solution culture containing 10−5 M abscisic acid (ABA) or gibberellic acid (GA3) (treated plants). Plasma membrane (PM) vesicles were isolated from the shoots of treated or control plants, and ATPase hydrolytic and proton-pumping activity, fluidity, and free sterol and phospholipid composition were determined. Both treatments resulted in modified plant growth and increases in PM fluidity. The ATPase hydrolytic activity was decreased by 25% of control values with ABA treatment and by 35% with GA3. Both treatments reduced proton-pumping by 23%. GA3 treatment reduced the relative amount (%) of stigmaster…
Hexacyanoferrate (III) stimulation of elongation in coleoptile segments fromZea mays L.
1995
The influence of exogenous potassium hexacyanoferrate (III) (HCF III) on elongation of maize (Zea mays L.) coleoptile segments was investigated. Addition of HCF III led to a strong stimulation of growth both in the presence and absence of indole-3-acetic acid (IAA). The magnitude of growth stimulation was dependent on the presence of IAA, HCF III concentration, incubation time, and phase growth. The reduced form, potassium hexacyanoferrate (II), was without effect on growth. In the presence of HCF III, elongation was suppressed when coleoptile segments were treated with N,N′-dicyclohexylcarbodiimide, cycloheximide or atebrine (quinacrine). The addition of HCF III stimulated the IAA-induced …
Changes in the Pi uptake and polyP accumulation in Saccharomyces cerevisiae strains deficient in the synthesis of trehalose and/or glycerol
2007
Abstract The intracellular level of free inorganic orthophosphate (P i ) in yeast cells generally depends on the P i uptake capacity, energy state of the cells in respect to the activity of the membrane-associated ATPases and on the activity of metabolic pathways involved in the production of glycerol and trehalose. Batch fermentation was performed to investigate the carbon substrate consumption, the P i uptake capacity and product formation by four Saccharomyces cerevisiae strains differing in their ability to produce glycerol and/or trehalose. The consumption of P i in mutant strains with a lack of the synthesis of the trehalose and/or glycerol exceeded the level for a wild type strain ab…
The effect of amphiphilic compounds on the secretion of levansucrase by Zymomonas mobilis
2005
Abstract The effect of some aliphatic (n-butanol to n-hexadecanol) and aromatic (benzyl and phenethyl alcohols), anesthetics (procaine) and surfactants (Tween 20 to Tween 80) on the secretion of levansucrase by the levan-producing strain of Gram-negative ethanologenic bacteria Zymomonas mobilis 113S were examined in this study. During incubation of Z. mobilis cells with sucrose (10 mM) a decrease of the levansucrase activity was observed in the presence of these amphiphilic compounds concomitantly with an increase of a total amount of protein in the medium. Since none of the compounds under study had any effect on enzyme activity in vitro observed structure- and concentration-dependent rela…
Coupling of proton translocation through ATPase incorporated into supported lipid bilayers to an electrochemical process
1997
Abstract H+-ATPase is incorporated into solid-supported lipid bilayers separated from the gold support by a peptide spacer. The translocation of protons across the lipid film to the inner side is coupled to the discharge of protons at the gold surface. The overall process is investigated by square wave voltammetry (SWV) and double potential-pulse chronoamperometry (CA). As a result, the formation of a proton gradient is monitored by SWV whereas currents measured by CA monitor the stationary state when the enzyme activity is directly coupled to the charge transfer at the electrode. These currents markedly depend on the number of ATPases present in the bilayer.
Screening for Solute Transporters in Plant Photosynthetic Membranes
2008
As compared to chloroplast envelope transporters, the field of thylakoid transporters is largely unexplored. There is evidence for several transport activities in the plant thylakoid membrane, but only a copper P-type ATPase and an ATP/ADP carrier have been so far identified at the gene level in Arabidopsis thaliana. Using in silico analyses, we have predicted the existence of approximately 15 thylakoid transporters, including phosphate transporters and cation channels. For experimental validation, we have used peptide- specific antibodies and functional analyses in heterologous system. These novel data are highly relevant to understand the transport network of the thylakoid membrane and it…