2.7 DNA Replication, Transcription and Translation

DNA Replication
1. Nature of Science
  1. Evidence for scientific theories
    1. Meselson and Stahl
      1. Semi-conservative replication of DNA
        Complementary base pairing
        Helicase
        Unwinds the double helix and separates the two strands by breaking H bonds
        DNA Polymerase
        Links nucleotides together to form a new strand, using pre-existing strand as a template
2. Polymerase chain reaction (PCR)
  1. Use of Taq DNA polymerase to produce multiple copies of DNA rapidly
Transcription
1. Synthesis of mRNA copied from the DNA base sequences by RNA polymerase
Translation
1. Synthesis of polypetides on ribosomes
  1. The amino acids sequence of polypeptides is determined by mRNA according to the genetic code
    1. Codons of three bases on mRNA correspond to one amino acid in a polypeptide
      1. Translation depends on complementary base pairing between codons on mRNA and anticodons on tRNA
      2. Use a table of the genetic code to deduce which codon corresponds to which amino acid
        Deducing the DNA base sequence for the mRNA strand
Aim 8
1. Ethical implications in altering the genome of an organism in order to produce proteins for medical use in humans
  1. Production of human insulin in bacteria as an example of the universal versatility of the genetic code allowing gene transfer between species

Resource summary

	Created by Steve Harton over 10 years ago