CA Lesson 2: DNA Replication PDF

Bell Ringer Explain the 3 major parts of DNA structure, including four nitrogenous bases.  Module 11, Lesson 2 Replication of DNA  Learning Objectives By the end of the lesson, students will be able to Describe the process of DNA replication with the help of...

Bell Ringer Explain the 3 major parts of DNA structure, including four nitrogenous bases.  Module 11, Lesson 2 Replication of DNA  Learning Objectives By the end of the lesson, students will be able to Describe the process of DNA replication with the help of enzymes. Differentiate between replication of DNA in Prokaryotes and Eukaryotes. Watch the Video and take notes then discuss How does DNA replicate?  Review Vocabulary Template: a molecule of DNA that is a pattern for synthesis of a new DNA molecule  DNA Replication- Semiconservative Replication Discuss and Summarize the role of various enzymes in DNA Replication.  Semiconservative Replication During semiconservative replication, parental strands of DNA separate, serve as templates, and produce DNA molecules that have one strand of parental DNA and one strand of new DNA.  Semiconservative Replication Semiconservative replication has three main stages: 1. Unwinding, 2. Base pairing 3. Joining. Semiconservative Replication 1. Unwinding DNA helicase, an enzyme, unwinds the helix, breaking the hydrogen bonds between bases. Single-stranded binding proteins keep the DNA strands separate during replication. RNA primase adds a short segment of RNA, called an RNA primer, on each DNA strand.  Semiconservative Replication 2. Base pairing The enzyme DNA polymerase adds appropriate nucleotides to the new DNA strand from the 3’ end. The leading strand is built continuously adding nitrogenous bases from 5’ to 3’ inward, and the lagging strand is built discontinuously adding bases from 5’ to 3’ outward in small segments called Okazaki fragments.  Semiconservative Replication 3. Joining DNA polymerase removes the RNA primer and fills in the place with DNA nucleotides. When the primer has been replaced, DNA ligase links the two sections. Comparing DNA Replication in Eukaryotes and Prokaryotes DNA Replication of DNA Replication of Eukaryotes Prokaryotes Eukaryotic DNA In prokaryotes, the unwinds in multiple circular DNA strand is areas as DNA is opened at one origin replicated. of replication. Individual Work: Complete the Worksheet given. Objective Check  Quiz 1 With what does the synthesis of a new strand. of DNA begin? A RNA primer CORREC T B nucleotide unit C messenger RNA D transfer RNA  Quiz 2 Which is true about the elongation of the. lagging strand? A does not require a C requires the template strand action of RNA ligase B produces Okazaki D proceeds by fragments continually CORREC adding T nucleotides to the 3’ end  Quiz 3 Which describes DNA replication in. prokaryotes? A does not require C moves in one DNA to unzip direction only B occurs in two D starts at multiple directions CORREC spots on a T chromosome  Quiz 4 Which catalyzes the addition of nucleotides to. a newly forming DNA strand? A DNA polymerase CORREC T B DNA ligase C DNA primer D RNA primer  Quiz 5 What best describes the DNA molecules. produced during the process of semiconservative replication? A They contain one strand of parental DNA and one strand CORREC of new DNA. T B They contain two new strands of DNA. C They contain two strands of parental DNA. D They contain one strand of combined parental DNA and new DNA.