Budding model

It can be said that science is the art of budding models to explain observations and predict new ones. Chemistry, as the central science, utilizes models ia virtually every aspect of the discipline. From the first week of a first chemistry course, students use the scientific method to develop models which explain the behavior of the elements. Anyone who studies or uses chemistry has, ia fact, practiced some form of molecular modeling. 

Fig. 11.3 Budding model for the biogenesis of intracellular LD. (A) LD formation is initiated by accumulation of TAG between the leaflets of the ER membrane. During budding of the forming LD, typical transmembrane proteins with hydrophilic domains protruding into the ER lumen and cytoplasm are segregated from membrane proteins, anchored in the outer leaflet, only, such as caveolin. After detachment of the matured LD from the ER...

Fig. 2.5 The two models of PHA granule formation in bacteria, a Micelle model and b Budding model. The irregular lines represent the polymer chains...

Figure 3.5 Models of polyester granule formation. (a) Micelle model (also representing the in vitro formation in the absence of phospholipids) and (b) budding model...

This model of Petty Swain (1985) is advanced and is clearly a valuable tool for tree breeders and managers. However, this model is essentially based on the individual tree and still needs to account for community and ecosystem properties such as canopy streamlining by leaf and twig flexing (Cionco, 1972). In addition, considerations of bud susceptibilities to... 

Various nonpremixed edge structures for symmetric cases (From Daou, R., Daou, ]., and Dold, J., Combust. Theory Model., 8,683,2004. With permission) (a) trihrachial, (b) cotton-bud shape, and (c) monobrachial structures and for asymmetric cases [19] (d) tribrachial and (e) bibrachial structures. 

The role of chaperone proteins in the folding of proteins is presented, and a model describing budding... 

The budding yeast Saccharomyces cerevisiae is an extremely attractive eukaryotic model system for the study of genes involved in iron metabolism. This is because of its short generation time, the ease with which relatively large amounts of... 

Lipids are transported between membranes. As indicated above, lipids are often biosynthesized in one intracellular membrane and must be transported to other intracellular compartments for membrane biogenesis. Because lipids are insoluble in water, special mechanisms must exist for the inter- and intracellular transport of membrane lipids. Vesicular trafficking, cytoplasmic transfer-exchange proteins and direct transfer across membrane contacts can transport lipids from one membrane to another. The best understood of such mechanisms is vesicular transport, wherein the lipid molecules are sorted into membrane vesicles that bud out from the donor membrane and travel to and then fuse with the recipient membrane. The well characterized transport of plasma cholesterol into cells via receptor-mediated endocytosis is a useful model of this type of lipid transport. [9, 20]. A brain specific transporter for cholesterol has been identified (see Chapter 5). It is believed that transport of cholesterol from the endoplasmic reticulum to other membranes and of glycolipids from the Golgi bodies to the plasma membrane is mediated by similar mechanisms. The transport of phosphoglycerides is less clearly understood. Recent evidence suggests that net phospholipid movement between subcellular membranes may occur via specialized zones of apposition, as characterized for transfer of PtdSer between mitochondria and the endoplasmic reticulum [21]. 

In the vesicular transport model, individual cisternae represent static structures [38]. Cargo is transported through the Golgi in the form of transport vesicles, which bud from one cisterna and fuse with the next. The vesicular transport model is consistent with the... 

TerwiUiger, T. (2003b) Automated side-chain model budding and sequence assignment by template matching. Acta Crystallogr. D 59, 45-49. 

The implementation of animal test protocols in the 1980s has been accompanied by the development of a host of alternative methods to study adverse effects of chemicals on reproductive and developmental parameters. For example, rat whole embryo culture stems from the seventies (16), as does the rat limb bud organ culture (17) and rat limb bud and brain micromass was developed in the eighties (18). An elegant nonvertebrate alternative model used regeneration of polyps of Hydra atUnuata from dissociated cells (19). Animal-free in vitro alternatives include those employing the proliferation of a human embryonic palatal mesenchymal cell line (20), the attachment of a mouse ovarian tumor cell line (21), and the differentiation of a neuroblastoma cell line (22) and a embryonal carcinoma cell line (23). Various overviews of methods have been published over the years (24). The predictability of... 

Hunter, T. Plowman, G.D. (1997) The protein kinases of budding yeast six score and more. Trends Biochem. Sci. 22, 18-22. Details of the variety of these important enzymes in a model eukaryote. 

Rodriguez Boulan, E. and Sabatini, D. D. 1978. Asymmetric budding of viruses in epithelial monolayers a model system for study of epithelial polarity. Proc. Natl. Acad. Sci, USA 75, 5071-5075. 

One parenteral cestode that is widely accepted as a model for cysticercosis caused by T. solium in humans is Taenia crassiceps, which is found as an adult in foxes and has a rodent intermediate host. Larval T. crassiceps reproduce by budding in the peritoneal cavity of mice and can be serially transferred from mouse to mouse. The immune response, which controls larval growth, relies on T cell-mediated immune mechanisms (Lopez-Briones et al., 2001) and treatments resulting in increased delayed type hypersensitivity led to greater resistance, while AB production was unaffected (Bojalil eta/., 1993). 

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