ANATOMY

Detailed explanation-1: -Ca2+ binds with the protein participating in muscle contraction to induce muscle contraction and is then reabsorbed into the sarcoplasmic reticulum via Ca2+ ATPase.

Detailed explanation-2: -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 Ca2+ electrochemical gradient across the cell membrane.

Detailed explanation-3: -Contraction of striated muscle results from a rise in cytoplasmic calcium concentration in a process termed excitation/contraction coupling. Most of this calcium moves back and forth across the sarcoplasmic-reticulum membrane in cycles of contraction and relaxation.

Detailed explanation-4: -REGULATION OF Ca2+ PUMPING IN HEART SARCOPLASMIC RETICULUM Calcium uptake by the SR represents the ATP-supported active calcium transport, which is carried out by the Ca2+-dependent ATPase, the major component of approximately 100, 000 daltons within the membrane of cardiac SR.