where does calcium ion storage occur in a cell
Calcium in biology Calcium storages are intracellular organelles, that constantly accumulate Ca2+ ions and release them during certain cellular events. Intracellular Ca2+ storages include mitochondria and the endoplasmic reticulum.[3] Characteristic concentrations of calcium in model organisms are: in E. coli 3mM (bound), 100nM (free), in budding yeast 2mM (bound), in mammalian cell 10-100nM (free) and in blood plasma 2mM.[4]
Resting potential In the case of the resting membrane potential across an animal cell's plasma membrane, potassium (and sodium) gradients are established by the Na+/K+-ATPase (sodium-potassium pump) which transports 2 potassium ions inside and 3 sodium ions outside at the cost of 1 ATP molecule. In other cases, for example, a membrane potential may be established by acidification of the inside of a membranous compartment (such as the proton pump that generates membrane potential across synaptic vesicle membranes).[citation needed]