DNA和RNA都是由核苷酸构成，每一单元为由三部分组成的分子，一端是磷酸盐，中部是一种糖，另一端是碱基。
DNA and RNA are made of nucleotides. Each unit is a three-part molecule with a phosphate at one end, a sugar in the middle and a variable nucleobase at the other end.
它还与核苷酸互换使用，尽管后者是由一个五碳糖、磷酸和一个碱基组成。
The term is also used interchangeably with “nucleotide” although the latter is composed of a five-carbon sugar joined to a phosphate group and one of the bases.
背景与目的：研究碱基切除修复基因XRCC1基因G28152A单核苷酸多态与肺癌风险的关系。
BACKGROUND&AIM: To evaluate the correlation between the single nucleotide polymorphism of XRCC1gene G28152A and the risk of lung cancer.
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