Unformatted text preview: The Replication of DNA Topics DNA Replication The Central Dogma of Biology Nucleic Acid Structure (again) SemiConservative Replication of DNA DNA during Replication Enzymes during Replication ProofReading Newly Copied DNA 1 The Important (Exam) Stuff Describe how much ATP is needed to power DNA replication and other key cell functions. Explain "The Central Dogma" of Biology. Describe the ONLY DNA replication mechanism. Describe DNA synthesis on the leading and lagging strand. List the key enzymes in DNA replication and their functions. Explain how mistakes are corrected during DNA replication. Biosynthetic Energy Requirements Escherichia coli
Macromolecule # per cell # per second Total ATP per second DNA 1 0.0001 RNA 15K 12.5 Protein 1.7M 1.4K Lipid 15M 12.5K Carbohydrate 39K 32.5 60K 75K 2.12M 87K 65K 2 The Central Dogma of Biology DNA> RNA> Protein Replication: DNA copies itself (with help) Transcription: DNA info to mRNA info Translation: mRNA, tRNA, rRNA & proteins make more proteins Review of Nucleotides base deoxyribose Deoxyribonucleotides (DNA) base ribose Ribonucleotides (RNA) 3 Advanced DNA/RNA Structure Antiparallel Strands RNA A + T G + C A + C G + T Complementary Base Pairing Possible Modes of DNA Replication Conservative Dispersive SemiConservative Possible Modes of DNA Replication Meselson and Stahl 4 What does E.coli DNA Replication look like? oriC locus Theta structure DNA Replication.1 5 DNA Replication.2 Leading/Continuous strand Lagging/Discontinuous strand DNA Replication.3 6 Enzymes and DNA Replication Helicase: ATPdependent unwinding of DNA SSB: singlestranded binding protein prevents DNA strand degradation RNA Primase: (RNA Polymerase) Builds RNA primers Topisomerase: Detangles DNA DNA Polymerase I: Replaces RNA primers with DNA DNA Polymerase III: Builds & proof reads DNA DNA Ligase: Ligates 3'OH of strand with 5'P of i Okazaki fragments The Replication Fork Helicase uses mucho ATP! 7 DNA Polymerase III DNA Polymerase III: The Movie 700 1,000 bases per SECOND DNAP III Activity depends on the presence of Mg+ 8 DNA Replication: The Fundamental & Advanced Versions Correcting the w istakes... DNA polymerase III detects mismatches based on helix diameter. The exonuclease subunit cuts out wrong and inserts correct bases. One in one billion bases gets repaired wrong. 9 Text References th Pages 176181 (11 Edition) 10 ...
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- Spring '08
- DNA, DNA DNA polymerase, DNA DNA ligase, Detangles DNA DNA, power DNA replication