BIOL 120 1st edition Lecture 18Outline of Last Lecture I. Experiment method and Five Element modelII. Monohybrid crossingIII. Principle of Segregation IV. Punnett Squares V. Dihybrid crossingVI. Human Blood Groups VII. Environmental influence and other main ideasOutline of Current LectureI. Overview of Genetic Material II. Review of DNAIII. DNA Replication Current LectureI. Over of Genetic MaterialA. Frederick Griffith (1928) studied two strands of pneumonia causing bacteria1. S strain caused pneumonia2. R strain did not cause disease 3. infected mice with these strains a). live S strain killed the mice and live R strain did notb). heated S strand did not kill the mice (virus was killed by heating)These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.c). combination of live R strain and heated S strain killed the mice (Combination allowed DNA of heated S strain to recover in the live R strain) a). known as transformationII. Review of DNA structureA. It is a nucleic acidB. Composed of:1. 5 carbon sugar 2. phosphate group (attached to 5’ carbon)3. nitrogenous bases (Adenine, thymine, cytosine, guanine)C. Nucleotides attach at 3’ with a phosphodiester bond (form between the phosphate group of one nucleotide and the 3’ OH of the next nucleotide)D. Strands grow in 5’ to 3’ direction E. Chargaff’s rule1. equal proportions of Purines (A and G) and Pyrimidines (C and T)a). amount of adenine = amount of thymineb). amount of cytosine = amount of guanine F. Rosalind Franklin1. Discovered that DNA is helical 2. used Wilkins’ DNA fibers to determine that a molecule of DNA has a diameter of 2nm and a complete turn of the helix occurs every 3.4 nmG. Watson and Crick1. proposed a double helix structure for DNA 2. did not actual experiment just used other’s research H. DNA is a double helix 1. A forms 2 hydrogen bonds with T2. G forms 3 hydrogen bonds with CIII. DNA ReplicationA. occurs in InterphaseB. DNA copies are semiconservative (part of the old strand bonded with new strand)C. Semiconservative theory proven by Meselson and Stahl (1958)1. grew cells in N15 and N142. DNA was extracted at different time intervals to view replication3. N15 is heavier than N14 location of N15 DNA was lower than N14 DNA and the semiconservative strand of N14 and N15 was in the middle proving it true D. Requires:1. Paternal DNA to copy (and primer)2. Enzymes to copy DNA3. NTPs (building blocks to make copy of DNA)E. Process1. Initiation2. Elongation (new strands of DNA are synthesized by DNA polymerase)3. Termination (replication stops)F. DNA polymerase (III)1. (III) is the only one used in DNA replication 2. matches existing DNA bases with complementary nucleotides 3. Features:a). adds new base to 3’ endb). synthesizes in 5’3’ directionc). requires a primer of RNA to
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