Granules disruption

In the 1940s, researchers identified that when starch is heated in water there were three distinct stages in the granule disruption process. During the first phase, water is slowly and reversibly absorbed by granules. 

Starch, Main sources, Macromolecular composition. Polymer structure and crystallinity. Granule disruption, Thermoplastic starch. Plasticization, Moisture uptake. Degradation, Blends, Composites... 

There are five prime factors that determine the properties of starches 1. starch is a polymer of glucose (dextrose) 2. the starch polymer is of two types linear and branched 3 the linear polymeric molecules can associate with each other giving insolubility in water 4. the polymeric molecules are organized and packed into granules which are insoluble in water and 5 disruption of the granule structure is required to render the starch polymer dispersible in water. The modification of starch takes into account these factors. 

Nusser, Z., Ahmad, Z., Tretter, V., Fuchs, K., Wisden, W., Seighart, W., and Somogyi, R (1999) Alterations in the expression of GABAa receptor subunits in cerebellar granule cells after the disruption of the a6 subunit gene. Eur. J. Neurosci. 11,1685-1697. 

Tretter, V., Hauer, B., Nusser, Z et al. (2001) Targeted disruption of the GABAa receptor 8 subunit gene leads to an up-regulation of y2 subunit-containing receptors in cerebellar granule cells. J. Biol. Chem. 276, 10532-10538. 

After administration of mercuric chloride to adult rat kidneys, several changes were found, for example, pars recta of the proximal tubular segment showing fragmentation and disruption of the plasma membrane, basophilic staining, vesiculation and disruption of endoplasmic reticulum and other cytoplasmic membranes, mitochondrial swelling, loss of mitochondrial dense granules and condensation of nuclear chromatin [223-225]. 

Experiments by Peter Elsbach and colleagues in the 1970s showed that although E. coli lost viability very quickly after incubation with neutrophils, these non-viable organisms still retained several important biochemical functions, such as membrane transport and macromolecular biosynthesis. As these functions are associated with the inner plasma membrane of the bacteria, these observations suggested that the lethal hit on E. coli by neutrophils occurred on the outer membrane. Because disrupted neutrophils also affected the bacteria in this way, it was concluded that the process was independent of the respiratory burst hence these workers investigated the granule proteins for the source of this activity (reviewed in Elsbach Weiss, 1983). 

Putaux, J. -L., Molina-Boisseau, S., Momaur, T., Dufresne, A. (2003). Platelet nanocrystals resulting from the disruption of waxy maize starch granules by acid hydrolysis. Biomacromol, 4,1198-1202. 

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