Describe briefly the biological importance of calcium and magnesium.

Explanation

An adult body contains about 25 g of Mg and 1200 g of Ca. The daily requirement in the human body has been estimated to be 200-300 mg.
(ii) Magnesium is the co-factor of all enzymes that utilize ATP in phosphate transfer and energy release.
The main pigment for the absorption of light in plants is chlorophyll which contains
magnesium
(iv) About 99% of body calcium is present in bones and teeth.
(v) Calcium plays important roles in neuromuscular function, interneuronal transmission, cell membrane integrity and blood coagulation.
(vi) The calcium concentration in plasma is regulated at about 100 mg `L^(-I)`. It is maintained by two hormones: calcitonin and parathyroid hormone. lt
(vii) Deficiency of magnesium results into convulsion and neuromuscular irritation.
(viii) 2% of adult weight is made up of calcium. Calcium phosphate is present in teeth and Calcium carbonate is present in bones. They make the teeth and bone hard.
(ix) Water in the human body such as inside the cell and in the blood contain dissolved calcium ions. These ions are involved in making muscles move and in sending electricity around the brain and along the nerves.
(x) Magnesium is an essential element in both plant and animal life