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Actinolite is an intermediate member in a solid-solution series between magnesium-rich tremolite, Ca 2 (Mg 5.0-4.5 Fe 2+ 0.0-0.5)Si 8 O 22 (OH) 2, and iron-rich ferro-actinolite, ☐Ca 2 (Mg 2.5-0.0 Fe 2+ 2.5-5.0)Si 8 O 22 (OH) 2. Mg and Fe ions can be freely exchanged in the crystal structure. Like tremolite, asbestiform actinolite is ...
Ca 2+ binding to these regulatory domains activates the transport of Ca 2+ across the plasma membrane. The structure of CBD1 shows four Ca 2+ ions arranged in a tight planar cluster. The structure of CBD2 in the Ca 2+ -bound (1.7 Å resolution) and Ca 2+ -free (1.4 Å resolution) conformations shows (like CBD1) a classical Ig fold but ...
The Ca 2+ concentration of the vacuole may reach millimolar levels. The most striking use of Ca 2+ ions as a structural element in algae occurs in the marine coccolithophores, which use Ca 2+ to form the calcium carbonate plates, with which they are covered. Calcium is needed to form the pectin in the middle lamella of newly formed cells.
The sodium-calcium exchanger (often denoted Na + /Ca 2+ exchanger, exchange protein, or NCX) is an antiporter membrane protein that removes calcium from cells. It uses the energy that is stored in the electrochemical gradient of sodium (Na +) by allowing Na + to flow down its gradient across the plasma membrane in exchange for the countertransport of calcium ions (Ca 2+).
In the simplest terms, mountain-building exposes calcium-bearing rocks such as basalt and granodiorite to chemical weathering and releases Ca 2+ into surface water. These ions are transported to the ocean where they react with dissolved CO 2 to form limestone (CaCO 3), which in turn settles to the sea floor where it is incorporated into new rocks.
The concentration of calcium (Ca 2+ ions) is normally several thousand times higher outside the cell than inside. Activation of particular VGCCs allows a Ca 2+ influx into the cell, which, depending on the cell type, results in activation of calcium-sensitive potassium channels , muscular contraction , [ 4 ] excitation of neurons, up-regulation ...
This is called calcium ammonium nitrate and often the name calcium nitrate prill is used as it always comes in a prilled (granular) form. Formulations lacking ammonia are also known: Ca(NO 3) 2 ·4H 2 O (11.9-0-0 + 16.9 Ca) and the water-free 17-0-0 + 23.6 Ca. A liquid formulation (9-0-0 + 11 Ca) is also offered.
10% calcium gluconate solution (given intravenously) is the form of calcium most widely used in the treatment of low blood calcium.This form of calcium is not as well absorbed as calcium lactate, [12] and it only contains 0.93% (93 mg/dL) calcium ion (defined by 1 g weight solute in 100 mL of solution to make 1% solution w/v).