Membranes, intracytoplasmic

Fig. 3-8 A thin section showing a eukaryotic cell. Note the nucleus (N) is bound by a nuclear membrane. In the cytoplasm of the cell are many mitochondria (M) and intracytoplasmic membranes. (Reprinted with permission from Richard Rodewald, Univ. of Virginia/Biological Photo Service.)...

In purple bacteria investigated thus far, the development of the photosynthetic apparatus which is controlled by the oxygen partial pressure is not influenced by light. However, the prevalent light intensity modifies the morphogenetic process of formation of intracytoplasmic membranes. Light intensity also controls the total bacteriochlorophyll concentration per cell and per membrane protein, as well as regulating... 

Two types of methane monooxygenases have been studied (1) soluble methane monooxygenase (sMMO) and (2) particulate (membrane-bound) methane monooxygenase (pMMO). The well-studied sMMO is produced by methanotrophs under copper-limiting conditions. All methanotrophs produce pMMO—found in intracytoplasmic membranes— but it is the less well-studied enzyme. 

Fig. 62. Calculated CD spectrum from the CD spectra of isolated Bchl-protein complexes. The calculated CD spectrum (solid curve) was the sum of the CD spectra of B 870-reaction center complexes and B800-850 complexes from high 850 intracytoplasmic membrane in the proportion determined by the least-squares method to give the best fit to the observed CD spectrum (open circles) of high 850 intracytoplasmic membrane 2081...

Although most strains of NH3-oxidizing and N02 -oxidizing bacteria have characteristic intracytoplasmic membrane structures, which can be visualized by electron microsocopy, it is not possible to distinguish the otherwise nondescript cells from other bacteria and archaea in water samples using standard microscopic techniques for ceU enumeration, e.g., epifluorescence microscopy with DNA fluorochromes. 

In green bacteria, there is no intracytoplasmic membrane rather the cell membrane carries on its inner surface special light-harvesting pigment assemblies known as chlorosomes which project into the cytoplasm. Chlorosomes are an important feature common to both green sulfur bacteria (Chlorobiaceae) and fdamentous green bacteria (Chloroflexaceae), as illustrated schematically in Fig. 1 ... 

Glycolipids moving along an identified axon of the marine mollusc, Aplysia californica, were synthesized and incorporated into intracytoplasmic membranes solely in the perikarion. Direct injection of tritiated sugar into the axon revealed no localized synthesis or exchange. There was no indication of any transfer into the axoplasm from the glia. The insertions of glycolipids into nascent membranes occurs co-ordinately with the insertion of protein components in the cell body. 

The ubiquinol-cytochrome c oxidoreductase (cytochrome bc complex) of Rhodobacter sphaeroides is an integral component of the intracytoplasmic membrane (ICM) and functions in light-driven cyclic electron flow and the conservation of radiant energy as an electrochemical proton gradient. Previous studies on the assembly of electron transfer constituents in/ , sphaeroides have demonstrated that complete cycles of electron flow do not occur merely upon insertion of newly synthesized reaction centers at sites of initiation of ICM growth, but instead, subsequent synthesis and assembly of redox centers of the be complex are required [1]. To further characterize the assembly process and for detailed structural investigations, the complex was purified and antibodies were raised against the isolated polypeptide constituents. In this report, results on the localization and levels of the feCj complex in various membrane fractions are presented a detailed description of the structurd work will appear elsewhere [2]. 

Annulate lamellae (Fig. 229) are intracytoplasmic membrane systems composed of parallel arrays of cisternae bearing at regular intervals small annuli or fenestrae. As shown by electron microscopy, the structure of the aimulate lamellae pore complex is similar to that of the pore complexes of the nuclear envelope. When melatonin was administered to rats or when rats were kept in darkness Freire and Cardinali (1975) observed changes in the ultra-... 

The methanotrophs have broadly been classified into two groups, type I and type II, on the basis of the carbon assimilation pathways in the metabolism of methane and on the arrangement of intracytoplasmic membranes. Two different metabolic strategies are utilized for the assimilation of carbon from formaldehyde formed in the course of the methane oxidation to carbon dioxide (Fig. 1). The type I bacteria involves the ribulose monophosphate pathway while the type II bacteria involves the glycine serine pathway. Recently, the Type I group has been further subdivided (type X), to accommodate strains... 

Resonance Raman (RR) spectroscopy can be used to yield information about ground state interactions assumed by bacteriochlorophyll a (BChl) in antenna structures of RhodospzvvttaZes, This technique permits investigations of the local environment of BChl molecules within the intracytoplasmic membrane and within antenna complexes, and, in particular, of their bonding with their host polypeptides (Lutz, 1981). Using this method, we studied chromatophores and antenna complexes of several species of Rhodospiritlaceae and Chromatiaoeae in order to compare, on a structural basis, complexes defined by their biochemical and electronic properties. 

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