What is arsenic methylation?
What is arsenic methylation?
Arsenic methylation contributes to the diversity of organoarsenic compounds, which have environmental effects. For example, methylated organoarsenicals play a significant role in controlling host bacterial populations and dominance in complex environments.
What are two main arsenic methylation pathways?
The main pathway is a straightforward bioactivation (metabolic activation) of arsenate in MMA, DMA and the theoretical conversion into TMA (not shown).
What is microbial methylation?
Microbial-methylation allows the conversion of aqueous or solid associated inorganic arsenic into gaseous arsines and removes them from the living medium, which is usually regarded as detoxification (Jia et al., 2013).
How does the body process arsenic?
Arsenic undergoes biomethylation in the liver. Approximately 70% of arsenic is excreted, mainly in urine [Rossman 2007]. Arsenic is excreted in the urine; most of a single, low-level dose is excreted within a few days after ingestion.
How is arsenic metabolized in the body?
Arsenic is mainly metabolized in the liver and excreted in the urine as methylated arsenicals [2, 3] and accumulated in the hair and nails [4]. The classical metabolic pathway of arsenic is generally accepted to proceed by repetitive reduction and oxidative methylation [5] (Fig. 2.1a).
What is the effect of arsenic on metabolism?
Arsenic exposure results in impairment of glucose metabolism, insulin secretion in pancreatic β-cells, altered gene expressions and signal transduction, and affects insulin-stimulated glucose uptake in adipocytes or skeletal muscle cells.
What is biological methylation?
The process by which a methyl radical (-CH3) is chemically combined with some other substance through the action of a living organism. One of the most environmentally important examples of this process is the methylation of mercury in the sediments of lakes, rivers, and other bodies of water.
What happens when arsenic enters the body?
Arsenic is a natural metalloid chemical that may be present in groundwater. Ingestion only poses health problems if a dangerous amount of arsenic enters the body. Then, it can lead to cancer, liver disease, coma, and death. Treatment involves bowel irrigation, medication, and chelation therapy.
What are the biochemical effects of arsenic?
The effects include death, inhibition of growth, photosynthesis and reproduction, and behavioral effects. Environments contaminated with arsenic contain only a few species and fewer numbers within species. If levels of arsenate are high enough, only resistant organisms, such as certain microbes, may be present.
What is the methylation process?
Methylation is a simple biochemical process – it is the transfer of four atoms – one carbon atom and three hydrogen atoms (CH3) – from one substance to another.
Where is arsenic metabolized?
the liver
Arsenic is mainly metabolized in the liver and excreted in the urine as methylated arsenicals [2, 3] and accumulated in the hair and nails [4].
How does arsenic get into cells?
Arsenate is taken up by phosphate transport systems. In contrast, at physiological pH, the form of arsenite is As(OH)3, which resembles organic molecules such as glycerol. Consequently, arsenite is taken into cells by aquaglyceroporin channels.
What is the methylation cycle?
The methylation cycle is a series of chemical changes that occur in the body, the primary purpose of which is to regulate neurotransmitters, regulate genetic repair and expression, and generate energy-rich molecules such as ATP. Many other important biological cyclical processes intersect with the methylation cycle.
How does methylation occur?
DNA methylation is a biological process by which methyl groups are added to the DNA molecule. Methylation can change the activity of a DNA segment without changing the sequence. When located in a gene promoter, DNA methylation typically acts to repress gene transcription.
How is arsenic metabolized?