Cytoplasm, definition

In addition to effects on biochemical reactions, the inhibitors may influence the permeability of the various cellular membranes and through physical and chemical effects may alter the structure of other subcellular structures such as proteins, nucleic acid, and spindle fibers. Unfortunately, few definite examples can be listed. The action of colchicine and podophyllin in interfering with cell division is well known. The effect of various lactones (coumarin, parasorbic acid, and protoanemonin) on mitotic activity was discussed above. Disturbances to cytoplasmic and vacuolar structure, and the morphology of mitochondria imposed by protoanemonin, were also mentioned. Interference with protein configuration and loss of biological activity was attributed to incorporation of azetidine-2-carboxylic acid into mung bean protein in place of proline. 

To meet the infectivity requirement in the definition of a prion, the abnormal form of the protein must be transmissible to other cells and organisms of the same species. In yeast and filamentous fungi, infectious agents such as viruses and plasmids are naturally transmitted by cytoplasmic mixing during mating or heterokaryon formation (Wickner, 2001). 

The idea that stimulated inositide metabolism was involved in increases in cytoplasmic Ca2+ was first proposed by Bob Michell (1975). To date, over 20 different inositol phosphates can be isolated from stimulated cells, but so far only one of these molecules can be ascribed a definite function Ins 1,4,5-P3, which is released into the cytoplasm following PLC hydrolysis of PIP2, liberates Ca2+ from intracellular stores. A role for Ins 1,3,4,5-P4in opening a Ca2+ gate , thus allowing the influx of Ca2+ from the external... 

In the previous paragraph changes occurring at the level of chromatin structure have been described. All these events cannot be considered from those taking place in the cytoplasm. Indeed, it is very likely that, albeit classical definition of apoptosis is based upon morphological criteria involving mainly the nucleus, cytoplasmic events are pivotal in determining the cellular fate after inadiation. 

In mouse liver and kidney and in rat liver, a-D-mannosidase activity appeared to be equally distributed between the two cytoplasmic-granule fractions. With mouse spleen and cancer tissue, a considerable proportion of the enzyme was found free in the cytoplasm. Rat spleen, on the other hand, lacked this cytoplasmic fraction. Inasmuch as the enzyme within the cytoplasmic granules was not fully active in a sucrose homogenate until the membranes had been disintegrated, a-D-mannosidase conforms to the definition of a lysosomal hydrolase. 

I Organisms without differentiation into definite nucleus and cytoplasm.KINGDOM MONERA... 

Backbone fluctuations with correlation times in the nanosecond regime are revealed in variations of the R1 residue scaled mobility, Ms, along the sequence (see Section III,A,1 for definition). Figure 15A (see color insert) shows a plot of Ms versus sequence for C1-C3, H8, and adjacent sequences in the TM helices. Figure 15B shows the cytoplasmic surface of rhodopsin color-coded according to Ms values. In this figure, C3 was modeled from the SDSL data, as in Fig. 9. 

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