Elements · ← As Arsenic · Br Bromine →
Selenium is built into enzymes as the amino acid selenocysteine.
| Symbol | Se |
|---|---|
| Atomic number | 34 |
| Standard atomic weight | 78.97 |
| Group | 16 |
| Period | 4 |
| Block | p-block |
| Category | Nonmetal |
| Standard state | Solid |
| Discovered | 1817 |
Source: PubChem, Selenium (periodic table data, retrieved 2026-10-19). Group and period follow the standard 18-column periodic table.
Rotruck and colleagues showed selenium is part of glutathione peroxidase: red cells from selenium-deficient rats lacked the enzyme's activity and could not protect haemoglobin from oxidative damage, and the purified enzyme held much of the cells' radioactive selenium-75.
As reported in: Rotruck, Pope, Ganther et al. (1973). Selenium: Biochemical Role as a Component of Glutathione Peroxidase. Science. doi:10.1126/science.179.4073.588
Abstract only
Chambers and colleagues found that the selenocysteine in the active site of mouse glutathione peroxidase is encoded by TGA, normally a termination codon.
As reported in: Chambers, Frampton, Goldfarb et al. (1986). The structure of the mouse glutathione peroxidase gene: the selenocysteine in the active site is encoded by the ‘termination’ codon, TGA.. The EMBO Journal. doi:10.1002/j.1460-2075.1986.tb04350.x
Found by name, common compounds and chemical formulas in each entry.
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