molecular genetics

dna, transcription and translation

What makes up DNA?

nucleotides, sugar and phosphate backbrone

Nucleotides

nitrogen bases

Deoxyribose

sugar

Transcription

Dna —> mRNA

• only uses a single strand of DNA

• RNA polymerase

• left with a single strand of mRNA that can be used for translation

Translation

• mRNA binds to ribosome in cytoplasm

• tRNA comes to P site, binds it’s anti-codon with the mRNA codon and leaves the amino acid

• tRNA from the A-site goes to P-site, binds, leaves amino acids and starts forming a polypeptide chain

• STOP codon

Polymerase Chain Reaction

increases number of copies if only a small sample

Gel Electrophoresis

seperates pieces of DNA based on size

Restriction enzymes

like molecular scissors and cut double-stranded DNA at a specfic base-pair sequence

DNA ligase

joins two strands of sticky ends

Recombinant DNA

fragments put together form at least two sources

DNA helicase

unwinds the double helix structure

DNA polymerase

adds nucleotides one by one to a growing chain

Leading strand

synthesized continously

Lagging strand

synthesized in fragments

Okazaki fragments

short, newly synthesized segments of DNA on the lagging strand