Effect Nitrogen metabolism

Smirnova and Moshkov have investigated the effects of the removal of leaves or buds and of grafting on the alkaloidal content of lupins, and Wallebroek has studied the alkaloidal and nitrogenous metabolism of Lupinus luteus seeds on germination. ... 

Numerous studies have shown that increased levels of UV affect photosynthetic activity (10-23), growth rate (24), nitrogen metabolism (25), and locomotion (26) of phytoplankton. Additionally, increases in UV-B are likely to alter community diversity as well as phytoplankton species composition. Thus, by weakening the base of the food web and altering trophodynamic relationships, UV-induced changes could potentially have far-reaching effects on the entire ecosystem. 

Figure 11.3 is a flow model representing in extremely simple form the main relevant features of nitrogen metabolism. It is not difficult to propose a sufficient explanation why Bprot is isotopically heavier than the diet. We might expect that the net effect of transamination and deamination of amino acids is to remove isotopically lighter N (Macko et al. 1987). That is to say, we may expect that the equilibrium constant for the reaction ... 

AO is also effective in metabolizing a wide range of nitrogen-containing heterocycles such as purines, pyrimidines, pteridines, quinolines, and diazanaphthalenes (95). For example, phthalazine is rapidly converted to 1-phthalazinone by AO and the prodrug, 5-ethynyl-2-(l//)-pyrimidone, is oxidized to the dihydropyrimidine dehydrogenase mechanism-based inhibitor, 5-ethynyluracil, by AO (Fig. 4.40) (96). 

Depth profiles from the eastern tropical North Pacific (Figure 24.8) show the effects of nitrogen metabolism under 02-deficient conditions. The thermocline is characterized by a sharp decline in O2 concentrations that coincides with increasing nitrate and phosphate concentrations. The oxycline is produced by the respiration of sinking POM under vertically stagnant conditions. Below the oxycline, in depths where O2 concentrations are suboxic, phosphate concentrations continue to increase, but at a slower rate. In contrast, nitrate concentrations decline and reach a mid-water minimum that coincides with a nitrite maximum. The latter is referred to as the secondary nitrite maximum. (At this site the primary nitrite maximum is located at 50 m.)... 

Hageman, R.H., Flesher, D. Gitter, A. (1961). Diurnal variation and other light effects influencing the activity of nitrate reductase and nitrogen metabolism in corn. Crop Science 1, 201-4. 

Doraiswamy, T. R., Singh, N., and Daniel, V. A. (1969). Effects of supplementing ragi (Eleusine coracana) diets with lysine or leaf protein on the growth and nitrogen metabolism of children. Br.. Nutr. 23, 737-743. 

G. N. Zaitseva and Li Tszyun-in (1961). The effect of X-rays on phosphorus and nitrogen metabolism in Azotobacter agile (in Russian). Mikrobiologiia, 30, 197-202. 

Parker, M. S., and Armbrust, E. V. (2005). Synergistic effects of light, temperature, and nitrogen source on transcription of genes for carbon and nitrogen metabolism in the centric diatom Thalassiosira pseudonana (BaciUariophyceae). J. Phycol. 41, 1142—1153. 

Berges, J. A., Varela, D. E., and Harrison, P. J. (2002). Effects of temperature on growth rate, cell composition and nitrogen metabolism in the marine diatom Thalassiosira pseudonana (BaciUario-phyceae). Mar. Ecol. Prog. Ser. 225, 139—146. 

Heterotrophic respiration fueled by the rain of organic matter from the surface ocean is ubiquitous in marine sediments. Its rate determines one of the important characteristics of the sedimentary environment the depth of redox horizons below the sediment-water interface. Heterotrophic respiration is the process by which carbon and nutrients are returned to the water column it is important in the marine fixed nitrogen and sulfur cycles and the accumulation of metabolic products sets the conditions for the removal of phosphorus from the oceans in authigenic minerals. A great deal of effort has been directed toward quantifying the rates, pathways, and effects of metabolism in sediments. 

Urea, the end product of nitrogen metabolism, accumulates rapidly in ARF. Most patients with ARF have a primary stressful illness that results in ureagenesis, and thus protein breakdown is markedly accelerated. Protein catabolism in ARF may be stimulated as the result of insulin resistance, metabolic acidosis, circulating proteases and inflammatory mediators, and the effects of uremic toxins. The mechanism may be direct, via modulation of protein synthesis, or indirect, by inhibiting the action of anabolic hormones. ... 

A. Kumar, R.P. Sinha, D.-P. Hader (1996). Effect of UV-B on enzymes of nitrogen metabolism in the cyanobacterium Nostoc calcicola. J. Plant Physiol, 148,86-91. 

R.P. Sinha, H.D. Kumar, A. Kumar, D.-P. Hader (1995). Effects of UV-B irradiation on growth, survival, pigmentation and nitrogen metabolism enzymes in cyanobacteria. Acta ProtozooL, 34,187-192. 

G. Dohler (1987). Effect of irradiation on nitrogen metabolism in marine diatoms and phytoplankton. Oceanis, 13,487-493. 

Karunanandaa, K., Varga, G. A. (1996). Colonization of rice straw by white-rot fungi (Cyathus stercoreus) Effect on ruminal fermentation pattern, nitrogen metabolism, and fiber utilization during continuous culture. Animal Feed Science and Technology, 61, 1-16. 

Behrend, J. and R.L Mateles Nitrogen metabolism in plant cell suspension cultures I. Effect of amino acids on growth Plant Physiol. 56 (1975) 584-589. 

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