BIOMOLECULES AND ENZYMES

Detailed explanation-1: -The bones act as a storage site for calcium: The body deposits calcium in the bones when blood levels get too high, and it releases calcium when blood levels drop too low. This process is regulated by PTH, vitamin D, and calcitonin. Cells of the parathyroid gland have plasma membrane receptors for calcium.

Detailed explanation-2: -Calcitonin decreases calcium levels by blocking the breakdown of bone calcium and by preventing your kidneys from reabsorbing calcium. In other words, it encourages calcium loss through your kidneys.

Detailed explanation-3: -Calcitonin reduces calcium levels in the blood by two main mechanisms: It inhibits the activity of osteoclasts, which are the cells responsible for breaking down bone. When bone is broken down, the calcium contained in the bone is released into the bloodstream.

Detailed explanation-4: -Parathyroid hormone regulates calcium levels in the blood, largely by increasing the levels when they are too low. It does this through its actions on the kidneys, bones and intestine: Bones – parathyroid hormone stimulates the release of calcium from large calcium stores in the bones into the bloodstream.