Structural Biochemistry/Alkali Earth metals
The Six Alkali Earth Metals are:
- Beryllium (Be)
- Magnesium (Mg)
- Calcium (Ca)
- Strontium (Sr)
- Barium (Ba)
- Radium (Ra)
Alkali Earth Metals are the elements in the second group of the periodic table. Elements in this group have such high melting points that some of them even remain solids in fires. Typically in ionic reactions, the alkali earth metals oxidize to a 2+ state since alla element in this period have two valence electrons. Two common salts are calcium chloride (CaCl2) and calcium oxide (CaO). 
Beryllium is a very lightweight and strong metal that is highly malleable. Beryllium is known to be a carcinogen, so long-term exposure can be deadly. Many of the effects include scarring of the lungs, lung disease, and eventual effects to the skin, spleen, liver, kidneys, and heart. Many symptoms include shortness of breath, chest pain, fever, night sweats, coughing up of blood, rapid heart beat, loss of appetite and loss of weight.
Magnesium is the 11th most abundant element in the body by mass. Its ions plan an essential role in manipulating important biological phosphate compounds such as ATP, DNA, and RNA. Numerous enzymes require magnesium ions in order to function. It is used medicinally in common laxatives and antacids. In plants, magnesium is at the center of chlorophyll, the structure that gives plants their green color.
Calcium is located in our bones and muscles. It serves to help muscles and nerves function, as well as to avoid blood clotting. We get it through eating foods such as any sort of dairy products, broccoli, figs and sardines.
Biomineralization is the biological process in which inorganic solid states of life such as bone, teeth, etc. is formed. Calcium is one of main types of biominerals involved in biomineralization.
Strontium is a solid silver white metallic element. It is chemically similar to calcium. Therefore, it is merged into bones at the site of increased osteogenesis. More interesting, ratio isotopes of strontium in teeth (87Sr/86Sr) are used to track animal migration and in the field of criminal forensics. Also, strontium chloride is sometimes used in toothpaste.
Barium is a silvery-white metal that can be found in the environment, where it exists naturally.Ii is very light and its density is half that of iron. Barium oxidizes in air, reacts vigoroulsy with water to form the hydroxide, liberating hydrogen. Barium reacts with almost all the non-metals, forming often poisouning compounds.
Radium, in its pure metallic form, is brilliant white when freshly prepared, but blackens on exposure to air, probably due to formation of the nitride. It exhibits luminescence, as do its salts; it decomposes in water and is somewhat more volatile than barium. Radium imparts a carmine red colour to a flame.
Alkaline earth metals are grouped in the periodic table due to very similar characteristics. They are the second group in the periodic table. They usually come with the oxidation state of +2, and therefore like to lose their outer two most electrons to forma a stable connection. All the alkaline earth metals are found on earth, hence their name. These alkaline earth metals are soft and silverish color coated, all with low densities, melting and boiling points. This is the general trend in this group of metals. The heavier alkaline earth metals react more quickly and vigorously than lighter alkaline earth metals. In some cases the reactions can be very quick, spontaneous and dangerous. Alkaline earth metals also have this phenomena where they emit different colors when burned. This means they show a different wavelength and can end in spectacular flame colors. These alkaline earth metals are also found in the human body and have great implications to their effects. They are essential to health. 
- Alkaline earth metals, November 14th, 2012.