DNA STRUCTURE + REPLICATION

• DNA is a double-stranded molecule composed of repeating molecules called nucleotides
• Nucleotides are composed of a deoxyribose sugar, a phosphate, and a nitrogenous base
• Polymerase Chain Reaction (PCR) amplifies DNA using complementary primers for specific target sequences
• After heating, DNA is cooled to between 50°C and 65°C to allow primers to bind target sequences
• Following cooling, DNA is heated to between 70°C and 80°C for heat-tolerant DNA polymerase to replicate
• Practical applications of PCR include solving crimes, settling paternity cases, and diagnosing genetic disorders
• DNA Replication Steps:

  • DNA is unwound and unzipped, breaking the hydrogen bonds between the bases
  • Primers attach to the 3' end
  • DNA polymerase leads the replication process continuously
  • DNA polymerase adds 3' to 5' DNA nucleotides using complementary base pairing to the 3' end of the new DNA strand
  • Lagging strand is replicated in fragments
  • Fragments of DNA are joined together by ligase