Biological Role and Precautions
Magnesium and calcium are ubiquitous and essential to all known living organisms. They are involved in more than one role, with, for example, magnesium or calcium ion pumps playing a role in some cellular processes, magnesium functioning as the active center in some enzymes, and calcium salts taking a structural role, most notably in bones.
Strontium plays an important role in marine aquatic life, especially hard corals, which use strontium to build their exoskeletons. It and barium have some uses in medicine, for example "barium meals" in radiographic imaging, whilst strontium compounds are employed in some toothpastes.
Beryllium and radium, however, are toxic. Beryllium's low aqueous solubility means it is rarely available to biological systems; it has no known role in living organisms, and when encountered by them, is usually highly toxic. Radium has a low availability and is highly radioactive, making it toxic to life.
Read more about this topic: Alkaline Earth
Famous quotes containing the words biological, role and/or precautions:
“If the most significant characteristic of man is the complex of biological needs he shares with all members of his species, then the best lives for the writer to observe are those in which the role of natural necessity is clearest, namely, the lives of the very poor.”
—W.H. (Wystan Hugh)
“A few [women] warrant our attention not because they have the answer but because they have rejected the mentality that insists there must be one answer. What makes them role models is not how much or how little they work, how many or how few hats they wear, but rather how well they understand, and accept, that for all rewards there will be commensurate sacrifice; for all gains, some loss; for any pleasure, some pain.”
—Melinda M. Marshall (20th century)
“A multitude of little superfluous precautions engender here a population of deputies and sub-officials, each of whom acquits himself with an air of importance and a rigorous precision, which seemed to say, though everything is done with much silence, “Make way, I am one of the members of the grand machine of state.””
—Marquis De Custine (1790–1857)