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  • Genomes
    • Nucleus of eukaryotic cell contains its chromosomes and is surrounded by a porous envelope
      • Different cell types have different transcriptomes and proteomes
      • Each human somatic cell contains 2 copes of each of the 21000 protein coding genes
      • Definitions
        • Telomere; Specialised DNA sequence at the end of linear chromosomes which maintain chromosomal integrity. Painted by telomerase
        • Contromere;  part of a chromosome that links sister chromatids. Where the kinetochore assembles
        • Replication origin; DNA sequence where replication is initiated
      • Kinetochore
        • Each kinetochore forms a plaque on the surface of the centromere. Their plus ends are embedded on to microtubules which form the spindle
          • Attachement site to microtubules contains a protein collar holding it tightly while still allowing polymerisation and depolymerisation
    • Replication
      • When both strands separated seen as a 'replication bubble'
      • When replication fork reaches end of linear chromosome there is no place to produce the RNA primer needed for last fragment at tip
        • Bacteria solve by having circular DNA and replicate in bidirectional fashion
        • Eucaryotes use telomeres to elongate tip in 5' 3' direction using an RNA template. After this extension, DNA polymerase can continue.
    • Genes
      • More complex organisms have lager genomes and genome increases as gene numbers does
        • Gene density declines as organisms becomes more complex. Internecine distances increase.
        • More complex organisms have similar exon sizes but more larger introns
          • E.g pufferfish Hungtingtin gene 7.5x larger than human equivalent due to larger introns (eons the same)
      • 1.5% of human genome is protein coding. 50% is repeated DNA sequences
        • The rest is evolutionary conserved


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