DNA Replication 

Chargaffs rules: A=T and C=G because of structures (life/genetic code)

Watson Crick model of DNA (1953)

Developed the 3D model of DNA

• Double helix- 2 chains of nuceiotides coiled around each other
• necleitides- structural compnents/building blocks of DNA and RNA
• hydrogen bonds- joins bases of chains, easy to break, importnat for replication

Importance of phosphates

1. linking bonds - connect 2 compounds
   • made up of phosphates and esters
   • stable
   • easily undone by enzymatic hydrolosis
2. Negatively ionized - after bonding one oxygen stays negative
   • negative charge acts as protection from breaking
   • keeps nucleotides and DNA within membranes

DUE TO negative charge → extremely insoluble in lipids

Steps of DNA replication

• Helicase unwinds and unzips the helix, to form the '“bubble”, many of them appear along the strand because otherwise the replication process would take way longer
• single-strand binding proteins latch onto the now single strnads of DNA to stop them from closing again
• DNA polymerse adds NEW nucleotides to the strand moving in the 5’ to 3’ direction (the leading strand) to line things up according to chargaffs rules