Q.Describe briefly the biological importance of Calcium and magnesium.

Step 1. A typical adult human body contains about 1200 g of calcium and about 25 g of magnesium, reflecting how central both ions are to normal physiology.

Step 2. Calcium is a major structural component of bones and teeth, giving them their rigidity.

Step 3. Calcium is also present in blood, at a concentration maintained by the hormones calcitonin and parathyroid hormone; a deficiency of calcium in the blood causes it to take longer to clot, and calcium is additionally important for muscle contraction.

Step 4. Magnesium serves as the cofactor for every enzyme that utilises ATP in phosphate transfer and energy release -- making it essential to cellular energy metabolism.

Step 5. Magnesium is also essential for DNA synthesis and for maintaining DNA's structural stability and proper functioning, and it helps balance electrolytes in the body (its deficiency causes convulsions and neuromuscular irritation). …

Cover calcium's roles (bone/tooth structure, hormone-regulated blood concentration, clotting, muscle contraction) and magnesium's roles (ATP-enzyme cofactor, DNA synthesis/stabili …

• Describing only calcium's bone-and-teeth role and only magnesium's chlorophyll role, missing the equally emphasised blood-clotting/muscle-contraction (Ca) an …