<prompt> The sodium- potassium pump is an example of:Active transpoPassive transpoFacilitated diffusionOsmosis  <response>: A i.e. Active transpo Calcium Metabolism in mammalian cells Concentration of intracellular Ca2 is 100 nmol L and it is about 12000 times less than that in extracellular fluid.Q Ca2 is stored in endoplasmic reticulum and mitochondria can be released from them to replenish cytoplasmic Ca2 Calcium binding proteins bind cytoplasmic Ca2 and when activated in this fashion, bring about a variety of physiological effect. Ca2 enter cell - Voltage gated Ca2 channels - Ligand gated Ca2 channels T L types - Store operated Ca2 channels SOCCs It is transpo out of cell by Active transpoQ i Ca2 IP ATPase antipoQ: cause 21-1 inside Ca2 outside of membrane at the cost of hydrolysis of ATP. ii Na Ca2 antipoQ : It is a counter transpo causes 3 Na inside 2Ca2 outsideQ of membrane. Calmodulin is Ca2 binding protein involved in contraction of smooth muscle. Passive transpo : when molecules traverse membrane by electro mechanical gradient Passively Unipo : Form of transpo where only one substance is transpoed. Sympo: Here binding of more than one substance to transpo protein substances are transpoed across the membrane together. Antipo: The transpo exchange one substance for another 