Not Your Usual Ion
“Drink your milk. It’s good for your bones.” We’re told this from early childhood, and with good reason. Milk contains a good supply of calcium, part of the structure of bone. However, there are two other ionic components of hydroxyapatite, the mineral component. Phosphate ion and hydroxide ion make up the remainder of the inorganic material in bone.
News You Can Use
- Bone is a very complex structure. It is composed of protein (mainly collagen), hydroxyapatite (a calcium-phosphate-hydroxide mixture), some other minerals, and contains 10-20% water. The calcium/phosphate ratios are not stoichiometric, but vary somewhat from one portion of bone to the next.
- Nitrate is a cation with a complex bonding structure. Major sources for this ion in drinking water are runoff from fertilizer, septic tank leakage, sewage, and natural deposits. High concentrations of nitrates represent a significant health hazard, especially to infants. The nitrate in the body is converted to nitrite, which then binds to hemoglobin. This binding decreases the ability of hemoglobin to transport oxygen, thus depriving the cells of the O2 needed for proper functioning.
- Cyanide production is widespread throughout nature. Forest fires will produce significant amounts of cyanide. Many plants contain cyanide, and it is produced by a number of bacteria, algae, and fungi. Cyanide is used industrially in metal finishing, iron and steel mills, and in organic synthesis processes. This material is also an important component for the refining of precious metals. Formation of a complex between cyanide and gold allows extraction of this metal from a mixture.
- Watch a video about bone structure at the link below:
Show What You Know
Use the links below to learn more about polyatomic ions. Then answer the following questions.
- Review the structures of polyatomic ions at the first listed web site.
- What carbonate components are present in bone?
- What is the maximum amount of nitrates allowed in water?
- How is cyanide biodegraded?
- What is the mechanism of cyanide toxicity?