paculla Posted December 3, 2010 Posted December 3, 2010 (edited) procitah prateci science rad.uvod je lep: Arsenic (As) is a chemical analog of phosphorus (P),which lies directly below P on the periodic table. Arsenicpossesses a similar atomic radius, as well as near identicalelectronegativity to P (5). The most common form of P in biology is phosphate (PO4), which behaves similarly toarsenate (AsO4) over the range of biologically relevant pHand redox gradients (6). The physico-chemical similaritybetween AsO4 and PO4 contributes to the biologicaltoxicity of AsO4 because metabolic pathways intended forPO4 cannot distinguish between the two molecules (7) andarsenate may be incorporated into some early steps in thepathways [(6) and refs therein]. However, it is thought thatdownstream metabolic processes are generally not compatiblewith As-incorporating molecules because of differences in thereactivities of P- and As-compounds (8). These downstreambiochemical pathways may require the more chemicallystable P-based metabolites; the lifetimes of more easilyhydrolyzed As-bearing analogs are thought to be too short.However, given the similarities of As and P, and by analogywith trace element substitutions, we hypothesized that AsO4 could specifically substitute for PO4 in an organismpossessing mechanisms to cope with the inherent instabilityof AsO4 compounds (6). Here, we experimentally tested thishypothesis by using AsO4, combined with no added PO4,to select for and isolate a microbe capable of accomplishingthis substitution.ref 6 je njen rad iz 2009. nacin na koji su dokazali zamenu fosfatne grupe sa AsO4 (ima li ovo neko ime?) je sto su izolovali proteine, lipide i DNK iz celije i izmerili koncentracije spektrometrijom i X zracima (ne znam kako se kaze xrd na srpskom). rezultati su vrlo jednoznacni jer se koncentracija As u DNK poveca za tri reda velicine u bakterijama izlozenim As. odnos As:P tako skoci sa 0.002 na 7.3. prilicno jednoznacno. Edited December 3, 2010 by paculla
fragand Posted December 3, 2010 Posted December 3, 2010 Wikileaks, pa varijacija Den Brauna. Sad, ako se nastavi logika, tj. ako skrivaju neko zesce sranje, mali nulearac (koreanci), ili ako nema bas nekog velikog sranja, onda bice Iran sve sa novim ekonomskim krahom.
paculla Posted December 3, 2010 Posted December 3, 2010 Wikileaks, pa varijacija Den Brauna. Sad, ako se nastavi logika, tj. ako skrivaju neko zesce sranje, mali nulearac (koreanci), ili ako nema bas nekog velikog sranja, onda bice Iran sve sa novim ekonomskim krahom.seres.
расејан Posted December 3, 2010 Posted December 3, 2010 (ne znam kako se kaze xrd na srpskom). Рендген.
gospa buba Posted December 3, 2010 Posted December 3, 2010 Рендген.дифракција икс зрака, млади човече!или иксерди, кад нас не слушају ^_^
papapavle Posted December 4, 2010 Posted December 4, 2010 jbte sad kad se pokupe popovi da krste mikrobe i bakterije. jedva cekam da vidim sta ce da kazu. ladno ce i raketle da pocnu da prave. Evo, počele visinske pripreme.
hooyadahoo Posted December 7, 2010 Posted December 7, 2010 http://www.youtube.com/watch?v=JrxMN7TAKq0&feature=channelkako kod da okrenes
dragance Posted December 7, 2010 Posted December 7, 2010 Cela ova jurnjava i hajp oko NASA KZS je u stvari jedan velikiJebi ga, resili ljudi da im treba jos novca od donacija i ko zna cega, pa da naprave malo interesovanja. Samo sto su taj zadatak dodelili Sheldonu pa je ispalo ovako kako jeste.
hooyadahoo Posted December 7, 2010 Posted December 7, 2010 izvini ali lupetas. ovo je zesce veliko otkrice.
dragance Posted December 7, 2010 Posted December 7, 2010 Ne kazem da nije zesce otkrice, ali najavili su ga kao Cecu na Grandu, a ljudi pomislili svasta. I na kraju ispade znacajno, ali za "obicni puk" ne bas toliko seksi. Shvatio sad?
Аврам Гојић Posted December 7, 2010 Author Posted December 7, 2010 Ne kazem da nije zesce otkrice, ali najavili su ga kao Cecu na Grandu, a ljudi pomislili svasta. I na kraju ispade znacajno, ali za "obicni puk" ne bas toliko seksi. Shvatio sad?pa i nisu poziv za kzs bio je smrtno precizan. blogosfera se sama od sebe napalila.
Takeshi Posted December 7, 2010 Posted December 7, 2010 A nije bas i da su naucnici odusevljeni:"This Paper Should Not Have Been Published"Scientists see fatal flaws in the NASA study of arsenic-based life
Fins fleet Posted December 7, 2010 Posted December 7, 2010 za zivot je samo jedan uslov "must": mora da postoji proces koji menja i oslobadja energiju. sve ostalo je na piscima sfa.Hehe, ovako je nasa nastavnica biologije u osnovnoj objasnila nastanak zivota: "Stvorio se enzim, koji je omogucio da kad pojedes svinju ne postanes svinja."
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