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Natural Organic Photosynthetic Solar Energy Transduction
Published in Sun Sam-Shajing, Sariciftci Niyazi Serdar, Organic Photovoltaics, 2017
The electrons extracted from water are donated to Photosystem II, and after a second light-driven electron transfer step by Photosystem I [8], eventually reduce an intermediate electron acceptor, the oxidized form of nicotinamide adenine dinucleotide phosphate (NADP+). Protons are also transported across the membrane and into the thylakoid lumen during the process of the noncyclic electron transfer, creating a pH difference, which contributes to the proton motive force. The energy in this proton motive force is used to make ATP. The NADPH and ATP that are formed in the light-driven steps of photosynthesis are used to fix CO2 to form sugars and other organic products that give energy for metablolism and growth of the organism. Excess stored energy is available to us in the form of food, fiber, and biomass.
Turfgrass Physiology and Environmental Stresses
Published in L.B. (Bert) McCarty, Golf Turf Management, 2018
Carbon dioxide is absorbed through leaf stomates. In addition to providing an entry of atmospheric CO2 into the leaf, stomates release H2O vapor during transpiration. Normally, stomates are open during the day or in the light and closed during the night or dark in an attempt to conserve H2O. The carbon in CO2 is in a highly oxidized state, whereas carbon in a carbohydrate such as sucrose is in a highly reduced state. The electrons that have been transported to NADP+, forming NADPH in the light reaction, are used to reduce the oxidation level of carbon during the dark reaction.
The Pentose Phosphates Pathway—Glucogenesis
Published in Jean-Louis Burgot, Thermodynamics in Bioenergetics, 2019
It consists of two parts. One is an oxidative part, the other being the non-oxidative one. In the oxidative part, NADP+ is the oxidant and is transformed into NADPH. The latter is used to reduce oxidized glutathione GSSG and also does reductive biosynthesis. Another product of the way is ribose-5-phosphate. It is a precursor for nucleotides, coenzymes and nucleic acids (Figure 98).
2,4-D mediated moderation of aluminum tolerance in Salvinia molesta D. Mitch. with regards to bioexclusion and related physiological and metabolic changes
Published in International Journal of Phytoremediation, 2023
Debabrata Dolui, Mirza Hasanuzzaman, Masayuki Fujita, Malay Kumar Adak
For wall and cytosolic invertase activity (E.C. 3.2.1.26), protein was purified with 80% ammonium sulfate cut and assayed according to Kaur and Zhawar (2021). Activity of NADP-ME (E.C. 1.1.1.40) was assayed by incubating in a buffer containing 60 mM Tris–HCl (pH 8.0), 10 mM MgCl2, 10 mM EDTA, 1 mM NADP–sodium salt, and protein extract (0.1 ml) at 30 °C following oxidation of reduced nicotinamide adenine dinucleotide phosphate (NADPH) at 340 nm (ε = 6.22 mM−1 cm−1) with 0.01 mM l-malate as substrate (Arias et al.2018). For NADP-malate dehydrogenase (MDH) (E.C. 1.1.1.37) activity, the purified protein was incubated in an appropriate assay buffer containing 25 mM HEPES [K+], pH 6.5, 10 mM MgSO, 1 mM Na, EGTA, 5 mM DTT, 1 mM PMSF, 5% (w/v) insoluble PVP, and 0.05% (v/v) Triton X-10 as suggested by Haque et al. (2022) and changes of absorbance at 340 nm for NADPH (ɛ = 6.22 mM−1 cm−1) with same substrate were recorded. The activity in-gel for protein polymorphisms for NADP-ME and MDH was done by separating on 10% native polyacrylamide gel electrophoresis in assay mixture containing 100 mM Tris–HCl (pH 7.8); 5 mM MgCl2; 1 mM EDTA; 1 mM dithiothreitol; and 0.01 mM l-malate. After reaction, gel was stained in a solution containing nitroblue tetrazolium (NBT) solution as described by Azzam et al. (2021).
Synthesis, characterization, X-ray structural analysis, DFT and BSA binding study of a Zn(II) complex, [Zn(II)Cl2(nia)2].2nia
Published in Journal of Coordination Chemistry, 2021
Anju Saini, Raj Pal Sharma, Parmjeet Kaur, Priti Bansal, Bal Krishan, Paramjeet Kaur, Valeria Ferretti, Pankaj Kandwal
Nicotinamide (aka niacinamide, vitamin B3 or pyridine-3-carboxylic amide) belongs to water soluble vitamin B family. The structure of nia indicates two potential coordinating atoms, i.e. nitrogen of pyridine and oxygen of carboxamide group (-CONH2); besides this the hydrogen present on the nitrogen atom can form hydrogen bonds. It is found in food and is also used as a dietary supplement in the form of medication. It is a precursor for two important coenzymes, nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP), which takes part in redox as well as metabolic reactions [12,13]. It is available as a generic medicine and used for the treatment of various diseases, i.e. hypercholesterolemia, pellagra, acne and certain psychological disorders [13]. Moreover, zinc complexes of nicotinamide have drawn great attention from researchers because of their biological importance [14,15].
Metal exposure and oxidative stress biomarkers in a Brazilian agricultural community
Published in Archives of Environmental & Occupational Health, 2022
Aline de Souza Espindola Santos, Rachel Ann Hauser-Davis, Rafael Christian Chávez Rocha, Tatiana D. Saint’Pierre, Armando Meyer
The Glutathione Reductase Assay Kit (Cayman Chemical, 703202) was used to assess the GR activity by measuring the NADPH oxidation rate. Briefly, 100 μL of the assay buffer (50 mmol L−1 potassium phosphate, pH 7.5, containing 1 mmol L−1 EDTA and 1.0 mg mL−1 bovine serum albumin), 20 μL of GSSG, and 20 μL of plasma sample were added to a test tube. The reaction was initiated by adding 50 μL of NADPH. The decrease in absorbance that followed the oxidation of NADPH to NADP+ was measured at 340 nm. GR activity results were then presented as (nmol/mL)/min.