DCMU
5477402
226118854
2008-07-16T22:10:11Z
Thijs!bot
1392310
robot Adding: [[cs:Diuron]]
{{Chembox new
| ImageFile = Diuron.png
| OtherNames = 3-(3,4-dichlorophenyl)-1,1-dimethylurea
| Section1 = {{Chembox Identifiers
| CASNo = 330-54-1
}}
| Section2 = {{Chembox Properties
| Formula = C<sub>9</sub>H<sub>10</sub>Cl<sub>2</sub>N<sub>2</sub>O
| MolarMass = 233.10 g/mol
| Density = 1.48 g/cm<sup>3</sup>
| MeltingPt = 158 °C
| BoilingPt = 180 °C
| Solubility = 42 mg/L
}}
| Section7 = {{Chembox Hazards
| EUClass = Harmful ('''Xn'''); Dangerous for the environment ('''N''')
}}
}}
'''DCMU''' ('''3-(3,4-dichlorophenyl)-1,1-dimethylurea''') is a [[herbicide]] that inhibits [[photosynthesis]]. It was released by [[Bayer]] in 1954 under the name of Diuron.
==Mechanism of action==
DCMU is a very specific and sensitive inhibitor of photosynthesis. It blocks the [[plastoquinone]] binding site of [[photosystem]] II, disallowing the electron flow from where it is generated, in photosystem II, to plastoquinone<ref>1</ref>. This interrupts the photosynthetic [[electron transport chain]] in photosynthesis and thus blocks the ability of the plant to turn light energy into chemical energy ([[adenosine triphosphate|ATP]] and [[reductant|reductant potential]]).
DCMU only blocks electron flow from photosystem II, it has no effect on photosystem I or other reactions in photosynthesis, such as light absorption or carbon fixation in the [[Calvin cycle]].
However, because it absorbs electrons [[oxidized]] from water in [[PS II]], the electron "hole" of [[PS I]] cannot be satisfied, effectively shutting down photosynthesis by blocking the reduction of NADP<sup>+</sup> to NADPH, and the cyclic photosynthetic pathway since electron shuttling is associated with proton pumping across the membrane into the [[lumen]].
==Applications==
Besides its use a herbicide, DCMU is often used to research energy flow in [[photosynthesis]].
==References==
{{Unreferenced|date =September 2007}}
<references/>
<ref>1</ref>''FEBS Letters'' (1986) '''205''', 269-274
[[Category:Herbicides]]
[[Category:Ureas]]
[[Category:Toxicology]]
[[cs:Diuron]]
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