Archaea: diferenças entre revisões
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=== Membrana celular ===
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[[Imagem:Archaea membrane.svg|thumb|right|300px|Membrane structures. '''Top''': an archaeal phospholipid, '''1''' isoprene sidechain, '''2''' ether linkage, '''3''' L-glycerol, '''4''' phosphate moieties. '''Middle''': a bacterial and eukaryotic phospholipid: '''5''' fatty acid, '''6''' ester linkage, '''7''' D-glycerol, '''8''' phosphate moieties. '''Bottom''': '''9''' lipid bilayer of bacteria and eukaryotes, '''10''' lipid monolayer of some archaea.]]
[[Imagem:Archaea membrane.svg|thumb|right|300px|Estrutura da membrana. '''Topo''': um fosfolípidio archaeal, '''1''' cadeia lateral de isopreno, '''2''' ligação de éter, '''3''' L-glicerol, '''4''' moléculas de fosfato. '''Meio''': um fosfolípidio bacteriano e eucariótico: '''5''' ácido graxo, '''6''' ligação de éster, '''7''' D-glicerol, '''8''' fração benzílica de fosfato. '''Abaixo''': '''9''' bicamada lipídica de bactéria e eucarióticas , '''10''' monocamada lipídica de algumas archaeas.]]
Archaeal membranes are made of molecules that differ strongly from those in other forms of life, which is evidence that archaea are related only distantly to bacteria and eukaryotes.<ref name=Koga/> In all organisms [[cell membrane]]s are made of molecules known as [[phospholipid]]s. These molecules possess both a [[chemical polarity|polar]] part that will dissolve in water (the [[phosphate]] "head"), and a "greasy" non-polar part that will not dissolve in water (the lipid tail). These dissimilar parts are connected by a [[glycerol]] group. In water, phospholipids cluster together, with the polar phosphate heads facing the water and the non-polar lipid tails facing away from the water. This causes them to assemble into layers. The major structure in cell membranes is a double layer of these phospholipids, which is called a [[lipid bilayer]].
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