Explain the significance of sodium , potassium, magnesium and calcium in biological fluids.

Explanation

The ions of alkali metals balance the charges associated with - vely charged organic molecule present in the cells. The ions help in maintaining the osmotic pressure in the cell. The presence of `Na^(+) and K^(+)` ions inside and outside the cell produces and electrical potential across the cell membrane. The presence of `Na^(+)` ions is associated with the movement of glucose into cells. The excess `Na^(+)` ions entering the cell are expelled in the pumping out process. The migration of amino acids is similar.
The `K^(+)` ions are essential for the metabolism of glucose inside the cell, the synthesis of proteins and the activation of certain enzymes.
`Mg^(+2)` ions are concentrated in animal cells. Enzymes like "Phosphohydrolases" and "Phosphotransferases" contain `Mg^(+2)` ions. These enzymes participate in ATP reactions and release energy. `Mg^(+2)` forms a complex with ATP. `Mg^(+2)` is a constituent of chlorophyll.
`Ca^(+2)` is present in bones and teeth as apatite. Enamel on teeth is Fluorapatite. `Ca^(+2)` ions are necessary for blood clotting. These are necessary to maintain regular heart beating. These are also necessary for muscle contraction.