Selenium
Selenium is the 34th element in the periodic table, with atomic mass of 78.96. It has its boiling point at 958.15K, and its melting point at 493.95K. [1]
Biology
It is the key element in selenocysteine (a cysteine amino acid where the sulphur atom is replaced by a selenium atom), an amino acid that occurs infrequently in proteins in both eukaryotes and prokaryotes.[2][3] Excessive selenium consumption can cause hair and nail loss, or breath that smells of garlic, whereas lack of selenium in the diet can cause male infertility, or generate a predisposition to Keshan or Kashin-Beck disease.[4] It is also added to some anti-dandruff shampoos as an anti-fungal agent.[5]
References
- ↑ Royal Society of Chemistry (2011), Selenium. http://www.rsc.org/periodic-table/element/34/selenium Last accessed 27/11/2014
- ↑ PubMed.gov (1991), Selenocysteine: the 21st amino acid, http://www.ncbi.nlm.nih.gov/pubmed/1828528 Last accessed 27/11/2014
- ↑ PubMed.gov (2012), Synthesis and decoding of selenocysteine and human health, http://www.ncbi.nlm.nih.gov/pubmed/23275319 Last accessed 27/11/2014
- ↑ National Institutes of Health (2013), Selenium Dietary Supplement Fact Sheet, http://ods.od.nih.gov/factsheets/Selenium-HealthProfessional/#h8 Last accessed 27/11/2014.
- ↑ Royal Society of Chemistry (2011), Selenium. http://www.rsc.org/periodic-table/element/34/selenium Last accessed 27/11/2014