鹼基配對原則

鹼基配對的原則是：（1）嘌呤鹼基專與嘧啶鹼基配對，而且腺嘌呤（A）專與胸腺嘧啶（T）配對（在RNA分子中，腺嘌呤專與尿嘧啶（U）配對）；鳥嘌呤（G）專與胞嘧啶（C）配對.（2）四種可能的鹼基對為A—T、T—A、G—C和C—G.A和T間構成兩個氫鍵，G和C間構成三個氫鍵.四種鹼基對的大小几乎相同.（3）配對的兩個鹼基之間是互補的，這樣有利於氫鍵的形成，對雙螺旋結構起穩定作用.鹼基配對原則，對DNA的半保留複製，具有特別重要的意義.它對遺傳信息的穩定傳遞提供了分子基礎.保證親代的遺傳信息完整地傳遞給子代，使子代獲得親代的遺傳性狀。

在DNA分子的雙螺旋結構中，位於兩條多核苷酸鏈上的嘌呤鹼基和嘧啶鹼基可以圍繞著螺旋軸通過形成氫鍵而互相搭配成對，鹼基間這種形式的結合，就稱為鹼基配對..In the doublehelixstructure ofDNAmolecules, located in more than two purine nucleotide chain bases and pyrimidine bases can be around the screwaxisthrough the formation of hydrogenbonds with each other in pairs, this form of integration between bases on the is called base pairing. base pairing principles are: (1) purine and pyrimidine bases specifically base pairing, and adenine (A) specifically with thymine (T) pairs (in the RNA molecules, adenine College and uracil (U) pair); guanine (G) College and cytosine (C) pair. (2) four possible base pairs for the A-T, T-A, G-C and C-G.A , and T form two hydrogen bonds between, G, and C constitute the three hydrogen bonds between. four kinds of base pairs is almost the same size. (3) matching between the two bases are complementary, so that is conducive to hydrogen bond formation of the double helix structure has a stabilizing effect. the principle of base pairing of the semi-conservative DNA replication, has a special significance. It passed the stability of the genetic information provides a molecular basis. to ensure parental generation of the genetic information passed to the son of a complete generation, so that offspring receive parental genetic trait.