Phosphorus turnover rates

Benitez-Nelson, C. R. and Buesseler, K. O. (1999). Variability of inorganic and organic phosphorus turnover rates in the coastal ocean. Nature 398, 502-505. 

E. L. Lim, K. G. Hollingsworth, P. E. Thelwall and R. Taylor, Measuring the acute effect of insulin infusion on ATP turnover rate in human skeletal muscle using phosphorus-31 magnetic resonance saturation transfer spectroscopy. NMR Biomed., 2010, 23,952-957. 

Before dealing with the different subcycles, one should perhaps consider a simplified model of the global phosphorus cycle shown in Fig. 3.2.1. The turnover rate of this cycle is regulated by the rate of diagenesis of phosphorus-containing sediments into phosphate rock. This process takes 0.1— 1 Gy (Broecker, 1974) which implies that a period of more than 1 Gy is... 

The chemical shift of the phosphorus resonance of various nucleotides has been studied as a function of pH in the presence and absence of RNase A. The signal shifts upheld on protonation of the phosphate and the apparent pATa of the phosphate group in 2 -CMP complex with RNase is the same as the pATa of histidine-119 in this enzyme as determined by n.m.r. From n.m.r. relaxation rates for the ternary complex manganese(n)-phosphate-E. coli alkaline phosphatase, it has been concluded that an outer-sphere complex is formed which has a shorter lifetime than the enzyme turnover rate. The latter conclusion is consistent with the participation of the complex in the enzymic reaction. 

Table 4 Turnover rates of dissolved Inorganic phosphorus (DIP) and dissolved organic phosphorus (DOP) In surface sea water ...

The effect of Roentgen rays on turnover rate of phosphatides present both in tissue and in nuclei was investigated as well. Two groups of twelve rats, after irradiation with 1000 r, are given labeled phosphate, while nonirradiated, control groups are treated in a similar way. After the lapse of two hours the animals are sacrificed and the sarcoma and livers are pooled separately. An aliquot is used in the determination of specific activities of inoi anic and phosphatide phosphorus of the tissue, while from the bulk of the material cell nuclei are isolated by the method of Bounce (42). The specific activities of the corresponding phosphorus fractions of the nuclei are also determined, and furthermore the activity of the inorganic phosphorus of the pooled blood plasma is measured. As seen in Tables XXXI and XXXII, the rate of turnover of phosphatides in liver... 

In view of the importance of desoxyribonucleic acid in cell division, the effect of roentgen rays on the turnover of desoxyribonucleic acid phosphorus was investigated (1,3,4,47). Roentgen radiation (100 r or more) was found to decrease turnover rate of desoxyribonucleic acid, in both Jensen sarcoma and normal organs. As seen in Table XXXVIII the amount of newly formed desoxyribonucleic acid molecules, found to be 2-3% in the course of two hours in nonirradiated, growing sarcoma, is reduced by irradiation to one-half to one-third of its normal value. These results are ob-... 

The rhodium catalyst was recycled batch-wise four times. It was found that a short induction period occurred during the first reaction cycle. The following cycles showed a constant rate and no loss of activity was detected. A ligand-to-rhodium ratio of 5 1 led to a constant yield of 95% per cycle after 1 h. Within the four cycles a total turnover number of 1000 with a maximum turnover frequency of 234 h was achieved. The leaching of rhodium and phosphorus into the aqueous layer was determined by inductively coupled plasma atomic emission spectrometry. Rhodium leaching amounted to 14.2 ppm in the first run, then dropped to 3.6 ppm (second run) and reached values of 0.95 and 0.63 ppm in the third and fourth runs, respectively. 

Rates of Turnover of 7 and / Phosphates of ATP If a small amount of ATP labeled with radioactive phosphorus in the terminal position, [7-32P]ATP, is added to a yeast extract, about half of the 32P activity is found in P, within a few minutes, but the concentration of ATP remains unchanged. 

Calcitonin is a peptide hormone produced by the C cells of the thyroid gland (in mammals). It acts on bone (inhibiting osteoclasis) to reduce the rate of bone turnover, and on the kidney to reduce reabsorption of calcium and phosphorus. It is obtained from natural sources (pork, salmon, eel), or S3mthesised. The t/ varies according to source t/ human is 10 min. Antibodies develop particularly to pork calcitonin and neutralise its effect synthetic salmon calcitonin (salcatonin) is therefore preferred for prolonged use loss of effect may also be due to down-regulation of receptors. Calcitonin is used (s.c., i.m. or intranasally) to control hypercalcaemia (rapid effect), Paget s disease of bone (relief of pain, and to relieve compression of nerves, e.g. auditory cranial), metastatic bone cancer pain, and postmenopausal osteoporosis. 

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