What is the function of NaCl in the body?

Question

What is this molecule's function? and why does the fact that it's an ionic bond help the molecule perform its function?

Answer 1

Sodium chloride is not strictly speaking a molecule as it has no covalent bonds, it is an ionic compound. Also in the body the two parts do not necessarily work together.

Sodium is mainly an electrolyte regulating fluid movements in blood, extracellular spaces and cells while its movement in and out of the neurons in relation to potassium is the basis of the electrical impulse in the nervous system. And some transport proteins in the cell mebrane require sodium to work eg the ones that pass amino acids into the gut cells.

The chloride ion is used as part of hydrochloric acid in the stomach and as a means to balance electrically red blood cells after bicarbonate ions leave them during gas exchanges (most carbon dioxide is converted to bicarbonate and leaves red blood cells to enter the plasma). Also works with some neurotransmitters such as glycine and GABA to enable their action.

Answer 2

Sodium is the major positive ion (cation) in fluid outside of cells. Sodium regulates the total amount of water in the body and the transmission of sodium into and out of individual cells also plays a role in critical body functions. Many processes in the body, especially in the brain, nervous system, and muscles, require electrical signals for communication. The movement of sodium is critical in generation of these electrical signals. Too much or too little sodium therefore can cause cells to malfunction, and extremes (too much or too little) can be fatal. A Normal blood sodium level is 135 - 145 milliEquivalents/liter (mEq/L), or in international units, 135 - 145 millimoles/liter (mmol/L).