Question

翻译 英译中

Polynucleotides are formed by the joining of nucleotides by phosphodiester bonds. The phosphodiester bond is the formal analog of the peptide bond in proteins. It serves to join, log of the peptide bond in proteins. It serves to join, as a result of the esterification of two of the three hydroxyl groups of phosphoric acid, two adjoining nucleotide residues. Two free hydroxyl groups are present in deoxyribose on the C3’ and C5’ atoms. Therefore these are the only hydroxyl groups that can participate in the formation of a phosphodiester bond. Indeed, it turns out that the nucleotide residues in DNA polynucleotides are joined together by 3’, 5’-phosphodiester bonds.
In some instances, polynucleotides are linear polymers. The last nucleotide residue at each of the opposite ends of the polynucleotide chain serves as the two terminals of the chain. It is apparent that these terminals are not structurally equivalent, since one of the nucleotides must terminate at a 3’-hyfroxyl group and the other at a 5’-gydroxyl group. These ends of the polynucleotides are referred to as the 3’ and the5’ termini, and they may be biewed as corresponding to the amino and carboxyl termini in proteins. Polynucleotides also exist as cyclic structures, which contain no free terminals. Esterification between the 3’-OH terminus of a polynucleotide with its own 5’-phosohate terminus can produce a cyclic polynucleotide.

Answer 1

多核苷酸是由核苷酸通过磷酸二酯键连接组成的。磷酸二酯键是蛋白质里的肽键的类似物。
它供应参与，蛋白质中的肽键记录。它供应参与，是二分之三磷酸的羟基的酯化结果，两个与核苷酸的剩余物相邻。三分之二的羟基出现在脱氧核糖的碳3和碳5原子上面，因为这是唯一能参与磷酸二酯键形成的羟基。的确，原来是DNA多核苷酸里的核苷剩余物被碳3，碳5磷酸二酯键连接起来。
在某些例子中，多核苷酸是线型高分子。在每个多核苷酸链另一端的最后的核苷酸充当链的两个终端。很显然这两个终端在结构上不是相同的，因为一个核苷酸必须在一个3’-羟基，另一个在碳5羟基上结束。这些多核苷酸的结束被称为3’和5‘终点，而且它们也许和蛋白质里的氨基和羧基终点相一致，多核苷酸同样以不包含任何自由终端的环状结构出现，有自己的5’磷酸盐的多核苷酸的3'-OH终点之间的酯化可以产生一个环状的多核苷酸。

Answer 2

正在形成的多聚核苷酸，核苷酸的磷酸二酯键连接。磷酸二酯键是蛋白质中的肽键正式的模拟。它服务的加入，注销的蛋白质肽键。这份文件为加入作为对三个羟基磷酸，两个相邻的两个核苷酸残基酯化的结果。两个自由羟基在对C3'和C5'原子脱氧核糖存在。因此，只有这些羟基团可以参与磷酸二酯键的形成。的确，事实证明，在DNA核苷酸，核苷酸残基加入了3'，5' -磷酸二酯键在一起。
在某些情况下，核苷酸是线性聚合物。在对面的每月最后核苷酸残基的多核苷酸链的两端为两个码头服务链。很明显，这些终端设备都没有，因为结构相当于一个核苷酸必须终止在3' - hyfroxyl组和在5' - gydroxyl组中的其他。这些两端的核苷酸被称为3'和the5'端，他们可以作为相应的氨基酸和蛋白质的羧基末端biewed。核苷酸还存在，循环结构，其中包含没有免费的终端。一间自己的5' -核苷酸的phosohate总站的3' - OH末端可产生酯化反应循环多核苷酸。