Lesson 5: Rest of Lesson

• Features of DNA:

  • 2 polynucleotide strands
  • Anti-parallel strands
  • Specific Pairing
• 3 RNA structure:

  • 1 polynucleotide strand
  • Sugar is D. ribose
  • No thymine but has uracil
• Steps in Replication Process:

  1. Initiation
  2. Elongation
  3. Termination
• Initiation starts with ori site
• Initiation forms single strand DNA
• Initiation requires helix unwinding
• Initiation has DNA Gyrase
• Elongation has 2 strands: leading and lagging strand
• Leading strand has primase and 11+1 nucleotide
• Leading strand has 10 to 60 for eukaryotes
• Leading strand has 5' to 3' direction
• Lagging strand has Primase to provide
• Lagging strand has several primers
• Lagging strand has 5' to 3' direction
• Okazaki fragments; prokaryotes have 1-2k nucleotides while eukaryotes have 100-200 nucleotides
• Ligase joins the phosphodiester bonds.
• Termination:

  two identical DNA molecules
• Helicase + primase = primosome
• Significance of replication:

  • faithful copying of DNA
  • identical to e/o
  • biological information