Biological transfers

Transfer of authority to regulate biologies transferred from NIH to FDA. The NIH... 

Unusual nucleophiles may also attack co-ordinated carbonyl groups. The biological interconversion of carbonyls and alcohols is usually achieved by hydride transfer catalysed by a metalloenzyme (see Chapter 10). The biological transfer agent is a dihydropyri-dine (NADH), which transfers a hydride to the carbonyl acceptor and forms a pyridinium salt (NAD+) (Fig. 3-23). 

Between 1902 and 1972, regulatory responsibility for biologies transferred several times, ultimately settling with FDA, as shown by this brief timeline of the relevant transfers ... 

All of the many biological transfer processes combine to determine a net surface resistance to transfer. Empirical relationships can be used to infer stomatal resistance from data on photosynthetically active radiation, water stress, temperature, atmospheric humidity and carbon dioxide levels. The resulting net surface resistance has been coupled with mathematical descriptions of aerodynamic and boundary-layer resistances in a "big leaf" model derived on the basis of agricultural and forest meteorology literature (4). At present, the big-leaf model is relatively coarse, permitting application only to areas dominated by maize, soybeans, grass, deciduous trees, and conifers. 

The electron transferring non-heme iron proteins can be strictly differentiated from those non-heme iron proteins and polypeptides such as ferritin and ferrichrome which act in biological transfer and storage of iron. They can be distinguished also from iron-flavoproteins, such as succinic dehydrogenase, which contain flavin in addition to the iron constituent. Nevertheless, in many chemical and physical aspects, the non-heme iron moiety of the iron-flavoproteins exhibits behavior similar to that of electron-transferring non-heme iron proteins. 

Contents indude regulatory perspective, technological approaches, human health risk assessments, biological transfer of contaminants in terrestrial ecosystems, sediment contamination, toxicity testing, and case studies. 

Fowler SW (1982) Biological transfer and transport processes. In Kullenbergg, ed. Pollutant transfer and transport processes. Volume II, pp. 1-65. CRC Press. 

The remarkable biological transfer of a methyl group from one metal to another in ACS catalysis has been modeled using a monomeric Ni complex, [ (tmc)]" ". ... 

The important role played by solitons in biological transfer remains to be clarified solitons are said to arise from localized disordered regions on, say, a membrane surface in the presence of the transmembrane electric field the local perturbation then tends to spread and to move leading to changes in the orientation of the lipid membrane molecules. The soliton energy is considerably below the energy band gap of a polypeptide chain but may initiate proton transfer in a hydrogen bonded chain in the presence of an electrostatic field. 

Xon-biological transfer of amino groups has also been effected between a-amino acids and the carbonyl of or-ketoacylamino acids (Herbst and Shemin, 94) no well-established instance of reactions of this type in enzymatic systems is known as yet. 

In recent years, the technique of mass spectrometry has been utiUzed to establish further instances of biological transfer of the intact methyl group. For example, [methyl-CDs] methionine was administered to seedlings of garbanzo (Cicer arietinum L.) and the deuterium content of the 4 -methoxy groups of certain 4 -methoxyisoflavones was determined by mass spectrometry. Almost all the deuterium in these methyl groups was present in the trideuterated species, with little or no dideuterated or... 

All of these biological functions of thiocystine can be attributed to the persulfide nature of the trisulfide. The term persulfide is used to describe compounds that can transfer sulfane sulfur to appropriate acceptors. On the basis of its similarity to thiosulfate in functioning as a substrate for rhodanese, other biological transfer reactions can be predicted for thiocystine. 

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