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匿名使用者 發問時間: 社會與文化語言 · 1 0 年前

急需英文翻譯高手,有關生化方面的!謝謝

英文高手~急需你們的翻譯阿~

英文太爛了!

有關生化方面的

希望不是用翻譯軟體翻壓~

謝謝!

Conductance of uncharged NH3, versus NH 4+ ion, can solve several

biological problems. First, because K+ channels conduct the very

similarly sized NH 4+ ion, there is the reverse possibility that an NH 4+

ion channel could "leak" potassium and hence leak membrane potential in eukaryotes. Amt/MEP proteins are not permeable to any other ions .

Transport of only uncharged NH3 and not NH 4+ assures this selectivity

against all ions that would require replacement for their hydration shell

while in the narrow portion of the channel. The energetic cost of

removing even a single water of hydration from an ion is prohibitive.

Second, NH 4+ or any other ion is progressively energetically unstable

as it approaches the center of the hydrophobic bilayer, whereas NH3 is

much less so because it is electrically neutral. Potassium channels for

example, have solved the problem by providing 16 carbonyl oxygens,

8 around each K+ ion position on the way into the channel (34). Each

oxygen offers a partial charge of 0.4 electrons to stabilize each K+ ion.

The KcsA channel also provides a water-filled cavity in the most

energetically costly position at the center of the bilayer (35). The narrow

hydrophobic channel of AmtB solves this energetic problem, as it also

selects against the ionic form of NH 4+ or any organic molecule larger in cross section than a single NH3. Third, passage of uncharged NH3

versus NH 4+ would not leak proton motive force in conduction. Thus,

neither energy nor any counter ion would be needed to accumulate

ammonia.

Note added in proof: In a recent publication, it is shown that Am

conductance by RhBG in oocytes is electroneutral, in contrast to the

currents reported by the same group for another homolog , and can

explain observations of electric currents in oocytes by an indirect

mechanism.

1 個解答

評分
  • 1 0 年前
    最佳解答

    電導uncharged氨氮,銀兩銨離子,可以解決幾個

    生物學問題。第一,因為鉀離子通道進行了非常

    同樣大小的銨離子,有一個反向的可能性,即一個信息NH 4 +

    離子通道能夠"洩漏"鉀,因此洩漏膜電位的真核生物。 AMT美國/優良蛋白質是不會滲透到任何其它離子。

    運輸的只有uncharged NH3和沒有信息NH 4 +保證這種選擇性

    對所有離子這將需要更換其水化殼

    而在狹窄的部分頻道。大力費用

    清除甚至單一的水從水化離子過高。

    其次,信息NH 4 +或任何其他離子正逐步大力不穩定

    因為它接近中心的疏水雙層,而氨氮是

    少得多,因為它是電中性的。鉀通道為

    舉例來說,有解決問題,提供16羰基氧,

    8日左右,每鉀離子的立場,並就未來路向渠道( 34 ) 。每次

    氧提供了部分收費0.4電子穩定相互鉀離子。

    該kcsa渠道,也提供了一個充水腔,在最

    大力昂貴的立場,在該中心的雙層( 35 ) 。狹義

    疏水渠道amtb解決了這個充滿活力的問題,因為它也

    選擇對離子形式中NH 4 +或任何有機分子較大,在截面比單一氨。第三,通過uncharged氨氮

    銀兩信息NH 4 +不會洩漏質子動力傳導。因此,

    既不是能源,也沒有任何反離子將需要積累

    氨。

    注意補充說,在證明:在最近出版的,它證明了很

    電導由rhbg在卵母細胞是electroneutral ,比照去

    電流報導,由同一組另一同源,並能

    解釋意見的電流,在卵母細胞的一個間接

    機制。

    這樣翻譯不知道你看不看的懂...希望能幫上你的忙@@~

    參考資料: 碰巧經過的我~
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