Selenium is a trace element that is essential in small amounts,
but can be toxic in larger amounts. Humans and animals require selenium for the
function of a number of selenium-dependent enzymes, also known as
During selenoprotein synthesis, selenocysteine is incorporated into a very
specific location in the amino acid sequence in order to form a functional
protein. Unlike animals, plants do not appear to require selenium for survival.
However, when selenium is present in the soil, plants incorporate it
non-specifically into compounds that usually contain sulfur