Cell division calcium

Catoptromers —. see Enantiomers Cell division calcium, 6.595 Cell membranes alkali metal transport, 3, 54 Cells labelled... 

In addition to its structural role in bone, and in teeth, the calcium ion is a carrier of chemical messages. It influences secretion, contraction of muscle, cell division, growth, transcription, as well as other key physiological processes. 

The role of calcium in cell division is controversial. The measurement of cation fluxes in synchronized cultures of Tetrahymena shows an influx of calcium 30 minutes prior to the initiation of cell division.440 However, there is also an influx of magnesium, and it has been suggested441 that the fluctuation of these metals during the synchronized division cycle is an effect rather than a cause. 

Calcium is necessary for cell division in Lactobacillus bifidus,445 and for the transition of L. bulgaricus446 from long filamentous chains to short bacilloid rods. 

Calcium ions are essential in a variety of physiological processes including blood clotting, release of neurotransmitter at the synapse, cell division, cell adhesion, secretion, bioluminescence, membrane permeability, muscle contraction, and bio-mineralization35,174 176. In most of these systems, the disposition and functions of membrane proteins are a key in transport and regulation of calcium. Thus in order to understand the functionality of calcium one should look at a membrane system where the biochemical interplay of calcium is known in detail. 

Preliminary studies also suggested that calcium channel blockers my increase the risk of cancer.10,28 Intracellular calcium levels are important in regulating cell division. By modifying calcium influx, calcium channel blockers could conceivably accelerate cell proliferation and lead to cancerous growths. Fortunately, the carcinogenic potential of these drugs has not been proven conclusively by subsequent studies.21 Hence, calcium channel blockers continue to be used cautiously but effectively in large numbers of patients. 

North Carolina State University, Crop Sciences Department Raleigh, NC Research on the mechanism of aluminum toxicity in plants. This study will determine the extent of aluminum accumulation inside cells at the root apex using microanalytical techniques and will define associated effects on cell division, cell expansion, and cellular accumulation of calcium and magnesium. U.S. Department of Agriculture... 

Vitamin D is necessary to allow the body to metabolize calcium and phosphorus effectively. Independent of the formation of vitamin D, it must be emphasized that excessive uptake of UV sunlight can lead to abnormal skin cell division and the possibility of skin cancer. 

The physiological role of PHB/polyP complexes has not been established, but bacterial cells like eukaryotic cells maintain low internal Ca2+,101-103,112 and there is increasing evidence pointing to calcium involvement in a number of important cellular functions, such as chemotaxis, cell division, heat shock, pathogenicity, and differentiation.104-107 Systems for calcium export have been identified.108-109 Mechanisms for calcium entry are less well known. An L-type channel was reported in Bacillus subtilis,n0 lu and Jones et al. and Holland et al.103,112 recently demonstrated the presence of a putative Ca2+ influx channel in stationary phase E. coli,... 

Calcium signaling plays a part in activating cells to engage in cell division, as well as in transforming normal cells to cancer cells. 

Calcium is used by the plant just prior to cell division - when the cell s chromosomes replicate themselves. Calcium is also used during cell growth. A trace of calcium is found in the tip of each root. 

The answer is c. (Murray, pp 238-249. Scriver, pp 2367-2424. Sack, pp 159-175. Wilson, pp 287-317.) A variety of agonists activate the plasma membrane-bound enzyme phospholipase C, which hydrolyzes the phosphodiester bond of phosphatidyl inositol 4,5-bisphosphate and consequently releases diacylglycerol (DAG) and inositol 1,4,5-triphosphate (IP3). Phospholipase C is also known as phosphoinositidase and as polyphosphoinositide phosphodiesterase. Both DAG and IP3 are second messengers. DAG activates protein kinase C, which is important in controlling cell division and cell proliferation. IP3 opens calcium channels and allows the rapid release of the calcium stores in endoplasmic reticulum (in smooth muscle, sarcoplasmic reticulum). The elevated levels of calcium ion stimulate smooth-muscle contraction, exocytosis, and glycogen breakdown. 

Davis AJ, Yan Z, Martinez B et al (2008) Protein phosphatase 2A is targeted to cell division control protein 6 by calcium-binding regulatory subunit. J Biol Chem 283 16104-16114... 

Calcium is essential to all living things. Calcium compounds are a vital component of the skeletons and bones of mammals, amphibians, reptiles, birds, fish, and other land and marine animals. The most abundant metal in the human body, calcium makes up the bones and serves other functions in the body s metabolic system. These functions include keeping cells joined together, aiding in muscle contraction and conduction of nerve impulses, helping blood clot, and controlling cell division. 

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