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DNA Replication and the Genetic Code 3.9

Semi conservative replication
1. DNA undergoes replication
  1. DNA helicase causes two strands to seperate by breaking the polynucleotide strands. The helix unzips.
    1. Each original strand acts as a template and free nucleotides are attracted to the bases
      1. Nucleotides and bases are joined together by DNA polymerase forming the sugar phosphate backbone. Hydrogen bonds form between bases
        2 identical strands form. All nucleotides form a complete polynucleotide
2. Proof
  1. Stahl and meselsohn experimented in 1958
Genetic Code
1. Triplet code - three nucleotides make up a triplet code. Also known as a codon
2. Universal
3. Scientists understood that proteins were made up of amino acids
4. Scientists understood that DNA must code for proteins and therefore carry instuctions
5. Scientists determined that DNA passed genetic information on
6. Eventually, they discovered DNA must code for a sequence of amino acids - the genetic code
Degenerate Code
1. There are 4 different bases meaning there are 64 possible codons
2. There is a starting codon and an ending codon
3. This prevents overlap meaning its non overlapping

DNA Replication and the Genetic Code 3.9

	Created by Harry Lovegrove over 5 years ago