**3. The revolution: Peering into the unseen**

#### **3.1 Case 1: The biology of selenium**

#### **3.1.1 Overview of selenium biochemistry**

Selenium exists, in mammals, primarily as part of selenomethionine or selenocystine, and less abundantly as selenite, selenide, monomethylselenol, dimethylselenide, trimethylselenonium, L-selenomethionine (SM), Se-methyl-L-selenocysteine. Because of its chemical similarity, it is utilized by the body in many of the same pathways as sulphur. Some controversy has surrounded its use as a nutritional supplement in the prevention of cancer – where it has been purported to function in an anti-oxidative capacity.
