医学生物化学简答题 考场必备（Medical biochemistry simplified answer examination room essential）.docVIP

医学生物化学简答题 考场必备（Medical biochemistry simplified answer examination room essential） Tenth chapters: 1. Briefly describe the process of DNA replication Under the action of topological foreign body enzyme and chain enzyme, DNA double helix structure opens, forming local single stranded, DNA binding protein and single stranded DNA binding, make single stranded DNA not renaturation. The The primers identify the replication initiation sites, and use four NTP as raw materials and single stranded DNA as template to synthesize RNA primer fragments according to 5 - 3 direction. The (III) at the 3 -OH end of RNA primers, DNA polymerase III catalyzes the synthesis of four dNTP with single stranded DNA as the template and 5 DNA 3 directions. The Under the action of DNA polymerase I, RNA primers were removed by hydrolysis, and the DNA fragment was extended by the enzyme to fill the vacancies. We will connect the two adjacent DNA fragments by DNA ligase, formed a complete chain of DNA. The 2, try to describe the basic law of DNA replication. A. semi reserved replication: when replicating, the parent chain double stranded DNA is released into two strands, each serving as templates to guide the offspring to synthesize new complementary strands. The DNA double strand of a daughter cell, in which a single strand is completely accepted from the parent, and the other strand is completely re synthesized. Because of base complementation, the DNA double strands of the two daughter cells are consistent with the parent DNA base sequence. This replication is called semi reserved replication. B. double copy: copy, DNA from the starting point to the direction of the two solution chain, forming two extending in the opposite direction of the replication fork, called bidirectional replication in prokaryotes are the starting point of the single bidirectional replication, eukaryotes is bidirectional copying multiple starting point. C. semi discontinuous replication: the two chains of DNA double heli