Bone marrow!!
it stores calcium
red blood cell
the smooth endoplasmic reticulum
Calcium is stored in bones, with a smaller amount in the blood, and in each cell.
The SER makes lipids, unlike the RER which makes proteins.
it produces energy and stores tanks of calcium ions.
To release insulin from the endocrine pancreas cells, the vesicles in the cell need calcium to bind to the internal cell membrane and eject their contents into the blood stream. If a person (or animal) is hypocalcemic (has low blood calcium levels), there isn't enough calcium in the pancreas cell to release the insulin.
Cell damage
They build bone matter using Calcium in the blood.
Sarcoplasmic reticulum stores and releases calcium ions within striated skeletal muscles.
Blood in, blood out.
makes and stores energy as ATP. Is the "powerplant" of a cell