A-Level的生物复习笔记第二弹,今天小编继续就给大家分享一下复习干活!
Part 2 . DNA replication
■ Occurs during interphase before the cell division to ensure each daughter cell get correct amount of genetic material.
■ DNA replicates by semi-conservative replication: Each daughter DNA molecule contains one strand from parent DNA and one newly formed strand.
■ Process:
1. The DNA double helix structure is unwound and unzipped by helicase.
2. Both separated DNA strands are used as the template strands.
3. Free nucleotides joined with templet strand and held by the hydrogen bonds between the complementary base pairs.
4. DNA polymerase catalyses the formation of the phosphodiester bonds between DNA nucleotides.
5. Due to the new DNA strands have to formed from 5’ end to 3’ end, and the DNA is antiparallel, one daughter DNA strand is formed discontinuously. The DNA segments are connected by the DNA ligase.
6. Two identical daughter DNA molecules are formed.
以上就是新航道重庆小编给大家分享的关于A-Level生物的相关内容。如果大家想要了解更多或者有任何疑问,欢迎联系新航道重庆学校。
新航道重庆学校官网:cq.xhd.cn
新航道重庆学校电话:400-185-9090
阅读推荐:
申请案例分享:如何被曼彻斯特大学商科录取?你有什么经验可以分享吗?
实用生活英语词汇分享:“降薪”、“工资”、“补偿”用英语怎么说?