The biological importance of Na, K, Mg and Ca in biological fluids is given as below:-
(i) An adult body contains 90 g of Na, 170 g of K, 25 g of Mg and 1200 of Ca.
(ii) Na+ and K+ ions participate in transmission of nerve signals in regulating the flow of water across the cell membrane and in transport of sugar and amino acids into the cell.
(iii) K+ Ions activate many enzymes to participate in the oxidation of glucose to produce ATP and with sodium are responsible for the tranmission of nerve signals and also help in protein synthesis.
(iv) Sodium ions are found primarily on the outside of cells, being coded in blood plasma and in the interstitial fluid which surrounds the cell whereas potassium ions are most abundant cations with in the cell fluids.
(v) M2+ions catalyse many enzymatic reaction. All enzymes that utilize ATP in phosphate transfer require magnesium as the cofactor.
(vi) The main pigment for obserbtion of light in plant is chlorophyll which contains magnesium.
(vii) About 99% to body calcium is present in bones and teeth.
(viii) Calcium plays an important role in neuromuscular function, inter neuronal transmission, cell membrane integrity and blood coagulation.
