Genera Mechanism

Several observations made in whole membranes or in the isolated complexes are in line with these concepts the shifts induced by antimycin A [110,137] and myxothiazol on the absorption spectra of cytochromes b and the alterations of the ESR spectrum of the FeS protein by UHDBT or DBMIB [131]. Moreover, the oxidant-induced reduction of cytochromes b, the key observation for accepting these electron transfer schemes, has been demonstrated in all h/c, complexes isolated so far from mitochondria [134], chloroplasts [111], cyanobacteria [112] and photosynthetic bacteria [110]. In the chloroplast b /f complex this reaction has been demonstrated also in the absence of any exogenously added quinol, indicating that possibly a structurally bound quinone (quinone is always present in the isolated complexes with a stoicheiometry of about 0.5-0.7 mol/mol of cyt. c, [110,111]) is sufficient to drive the reduction of cytochromes [138]. Since a detailed treatment of the genera] mechanism, as well as of the more specific problems of the mitochondrial respiratory chain, are reported in Chapter 3 of this volume, the following discussion will deal only with the specific features of the electron transfer chains in photosynthetic membranes. 

Fig- 25. A genera] mechanism of P replacement and P elimination-deamination reactions involving a common aminoacrylate intermediate (1). 

Class Representative family Mechanism Genus or species... 

Cone snails have generated a remarkably wide array of toxins. A variety of data suggest that this genus may use novel mechanisms for evolving diverse cysteine-rich peptides. 

Pakchung AAH, Soe CZ, Codd R (2008) Studies of Iron-uptake Mechanisms in Two Bacterial Species of the Shewanella Genus Adapted to Middle-range (Shewanella putrefaciens) or Antarctic Shewanella gelidimarina) Temperatures. Chem Biodivers 5 2113... 

A number of antibiotics produced by fungi of the genus Cephalosporium have been identified. These antibiotics called cephalosporins contain, in common with the penicillins, a p-lactam ring. In addition to the numerous penicillins and cephalosporins in use, three other classes of p-lactam antibiotics are available for clinical use. These are the carbapenems, the carbacephems, and the monobactams. All 3-lactam antibiotics have the same bactericidal mechanism of action. They block a critical step in bacterial cell wall synthesis. 

Hills, H. G., Williams, N. H. and Dodson, . H. (1972). Floral fragrances and isolating mechanisms in the genus Catasetum (Orchidaceae). Biotropica 4 61-76. 

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