Nucleic Acids

Puridimes definition

Double ring nitrogenous base → A & G

Pyrimidines definition

Single ring nitrogenous bases → T & C

5’ has what molecular compound?

Phosphate

3’ has what compound?

OH-

Helicase

Unwinds DNA helix

Primase

Primes strands with RNA

Topoisomerase

Loosens the double helix

DNA polymerase III

Adds nucleotides to the 3’ end of daughter strand

DNA polymerase I

Replaces primer RNA with nucleotides

Ligase

Bonds nucleotide segments together

DNA polymerase II

Proof-reads DNA

Telomeres

Postpone erosion at the ends of DNA - prevents shortening (non coding sequence)

Thymine Dimers

UV light exposure causing 2 adjacent thymine residues to become covalently linked

Telomerase

Adds telomeres/nucleotides to the ends of the DNA