288
T3D0287
Gallium arsenide
Gallium arsenide is a chemical compound of gallium and arsenic. It is used to make devices such as microwave frequency integrated circuits, infrared light-emitting diodes, laser diodes and solar cells. It is also a semiconductor. Arsenic is a chemical element that has the symbol As and atomic number 33. It is a poisonous metalloid that has many allotropic forms: yellow (molecular non-metallic) and several black and grey forms (metalloids) are a few that are seen. Three metalloidal forms of arsenic with different crystal structures are found free in nature (the minerals arsenopyrite and the much rarer arsenolamprite and pararsenolamprite), but it is more commonly found as a compound with other elements. (T3, L354)
1303-00-0
14770
AsGa
143.847180
Dark grey solid.
1238°C (1511°K)
Oral (L2) ; inhalation (L2); dermal (L2)
Arsenic and its metabolites disrupt ATP production through several mechanisms. At the level of the citric acid cycle, arsenic inhibits pyruvate dehydrogenase and by competing with phosphate it uncouples oxidative phosphorylation, thus inhibiting energy-linked reduction of NAD+, mitochondrial respiration, and ATP synthesis. Hydrogen peroxide production is also increased, which might form reactive oxygen species and oxidative stress. Arsenic's carginogenicity is influenced by the arsenical binding of tubulin, which results in aneuploidy, polyploidy and mitotic arrests. The binding of other arsenic protein targets may also cause altered DNA repair enzyme activity, altered DNA methylation patterns and cell proliferation. (T1, A17)
Arsenic is absorbed mainly by inhalation or ingestion, as to a lesser extent, dermal exposure. It is then distributed throughout the body, where it is reduced into arsenite if necessary, then methylated into monomethylarsenic (MMA) and dimethylarsenic acid (DMA) by arsenite methyltransferase. Arsenic and its metabolites are primarily excreted in the urine. Arsenic is known to induce the metal-binding protein metallothionein, which decreases the toxic effects of arsenic and other metals by binding them and making them biologically inactive, as well as acting as an antioxidant. (L20)
LD50: 4700 mg/kg (Intraperitoneal, Mouse) (T14)
1, carcinogenic to humans. (L135)
Gallium arsenide is used as a semiconductor, as well as in solar cells, x-ray detection diodes, and laser diodes. (L354)
Acute Oral: 0.005 mg/kg/day (L134)
Chronic Oral: 0.0003 mg/kg/day (L134)
Chronic Inhalation: 0.01 mg/m3 (L134)
Arsenic poisoning can lead to death from multi-system organ failure, probably from necrotic cell death, not apoptosis. Arsenic is also a known carcinogen, esepcially in skin, liver, bladder and lung cancers. (T1, L20)
Exposure to lower levels of arsenic can cause nausea and vomiting, decreased production of red and white blood cells, abnormal heart rhythm, damage to blood vessels, and a sensation of burn (T1).
Arsenic poisoning can be treated by chelation therapy, using chelating agents such as dimercaprol, EDTA or DMSA. Charcoal tablets may also be used for less severe cases. In addition, maintaining a diet high in sulfur helps eliminate arsenic from the body. (L20)
2009-03-06T18:58:27Z
2014-12-24T20:21:28Z
Metallothionein-2 (P02795)
Metallothionein-1G (P13640)
Metallothionein-1H (P80294)
Metallothionein-3 (P25713)
Metallothionein-1F (P04733)
Metallothionein-1E (P04732)
Metallothionein-1X (P80297)
Metallothionein-1A (P04731)
Metallothionein-1B (P07438)
Metallothionein-1M (Q8N339)
Metallothionein-4 (P47944)
Metallothionein-1L (Q93083)
Arsenite methyltransferase (Q9HBK9)
(L92)
http://en.wikipedia.org/wiki/gallium arsenide
C043055
Gallium arsenide
true
Arsenite methyltransferase (Q9HBK9)
(L92)
Metallothionein-2 (P02795)
Metallothionein-1G (P13640)
Metallothionein-1H (P80294)
Metallothionein-3 (P25713)
Metallothionein-1F (P04733)
Metallothionein-1E (P04732)
Metallothionein-1X (P80297)
Metallothionein-1A (P04731)
Metallothionein-1B (P07438)
Metallothionein-1M (Q8N339)
Metallothionein-4 (P47944)
Metallothionein-1L (Q93083)
(L92)
[Ga]#[As]
AsGa
InChI=1S/As.Ga
InChIKey=JBRZTFJDHDCESZ-UHFFFAOYSA-N
144.645
143.847177329
Exogenous
Solid
14087