Calcium pump Calcium pump Calcium pumps are a family of ion transporters found in the cell membrane of all animal cells. They are responsible for the active transport of calcium out of the cell for the maintenance of the steep Ca electrochemical gradient across the cell membrane. Calcium pumps play a crucial role in proper cell signalling by keeping the intracellular calcium concentration roughly 10,000 times lower than the extracellular concentration. Failure to do so is one cause of muscle cramps. The plasma membrane Ca ATPase and the sodium-calcium exchanger are together the main regulators of intracellular Ca concentrations. Ca has many
Calcium metabolism dairy product and eggs, as well as in tinned fish products. The calcium contained in vegetable matter is often complexed with phytates, oxalates, citrate and other organic acids, such as the long-chained fatty acids (e.g. palmitic acid), with which calcium binds to form insoluble calcium soaps. Although calcium flow to and from the bone is neutral, about 5–10 mmol is turned over a day. Bone serves as an important storage point for calcium, as it contains 99% of the total body calcium. Calcium release from bone is regulated by parathyroid hormone in conjunction with calcitriol manufactured in the kidney under