Question

What effect does increased cytosolic Ca2+ have in the cytoplasm? Where does the calcium
come from and where does it return?

Answer 1

Calcium signalling is the use of calcium ions (ca2+) to communicate and drive intercellular processes often as a step in signal transduction. ca2+ is important for cellular signalling, for once it enters the cytosol of the cytoplasm it exerts allosteric regulatory effects on many enzymes and proteins. ca2+ can act in signal transduction resulting from activation of ion channels or as a second messenger caused by indirect signal transduction pathways such as G protein-coupled receptors.

They make their entrance into the cytoplasm either from outside the cell through the cell membrane via calcium channels ( such as calcium-binding proteins or voltage-gated calcium channels), or from some internal calcium storages such as the endoplasmic reticulum and mitochondria.

The low concentration of calcium in the cytosol allows calcium ions to function as a second messenger in calcium signalling. here, a signal such as a hormone or an action potential opens calcium channel so that calcium floods into the cytosol.

Calcium is not made in the body -it must be absorbed from the foods we eat. To effectively absorb calcium from food,our bodies need vitamin D . if we do not have enough calcium in our diets to keep our bodies functioning,calcium is removed from where it is stored in our bones.The bone stores 99% of the body's calcium and 85% of the phosphorus.it is very important to keep the blood level of calcium within a narrow range.