Genetics

History
1. Gregor Mendel - Pea plants 1866
2. Johann Friedrich Miescher DNA
deoxyribonucleic acid
1. nuclein was rich in phosphorus and was acidic
  1. Nucleases are enzymes that act on nucleic acids
  2. DNA / RNA
    1. polymers made up of monomer s callednucleotides
    2. DNA/RNA polymers made up of monomers called nucleotides
      1. Five-carbon-ring sugar (deoxyribose or ribose) Phosphate group Nitrogen base
      2. Nitrogen Bases Differences
        RNA
        Uracil
        DNA
        Thymine (T for two bonds/ G for three)
        Both have - Adenine - Cytosine - Guanine
Molecular Genetics
1. Gene Expression
  1. Antibodies bind to specific foreign particles, such as viruses and bacteria, to help protect the body. Immunoglobulin G (IgG) Example of expression for protein
    1. 20 different types of amino acids
      1. transcription and translation = Gene expression
        Messenger RNA
        Transfer RNA
        Start and stop codons
        AUG (STOP) Methionine
        UUG / GUG (START) Valine / luecine
2. Genetic code
  1. UGG - Tryptophan
    1. UGA - Opal
    2. UGU - Cysteine
    3. ALL RNA
  2. DNA code table U replaced by T
3. Genetic engingeering
  1. Dna inserted into host genome (Commonly a phage)
    1. Phage (Bateriophage) cell that attacks bacteria
    2. Isolating and copying genetic material
      1. Molecular cloning
  2. Gene targeting
    1. Delete and add genes / remove exons
      1. = Homolougous recombination
      2. point mutations
  3. GM - Mice (oncomouse ) used for many experiments - Cancer - diabetes
  4. Gene therapy
    1. Replacing defective genes in humans ( Germline gene therapy )
      1. Somatic gene therapy - used for Parkinsons disease
  5. Cloning of any DNA fragment essentially involves four steps 1 fragmentation - breaking apart a strand of DNA 2 ligation - gluing together pieces of DNA in a desired sequence 3 transfection - inserting the newly formed pieces of DNA into 4 cells screening/selection - selecting out the cells that were successfully transfected with the new DNA
The basics
1. Genes
  1. Total genes in an organism = Genome (can be multiple sites)
    1. Each gene is located on the chromosome = a locus (site)
  2. 23 pairs = 46 chromsomes = one human
    1. 22 Automsomes in both female and male -
      1. XX in Females (23rd pair differ)
      2. XY in Males (23rd pair differs)
      3. More SRY (sex-determining region Y) means male offspring
  3. Mitosis and mieosis
Transcription
1. Translation
  1. Similar to transcription but no replication of DNA instead = rRNA
    1. tRNA is used as well
      1. Location: Nucleus in transcription - cytoplasm in translation
        Terminator
        Three top stop codons cause this
2. mRNA copies the DNA message
  1. mRNA (messenger RNA) takes the message to the nucleus
    1. The steps; get ready to transcribe, enzymes find right DNA. DNA is opened up (initiation) followed by the building of mRNA (elongation) then the DNA molecules snap shut to release the mRNA (termination)
      1. Promoter
      2. Terminator
        RNA transcript causes this
Technology to manipulate DNA
1. PCR ( polymerase chain reaction )
  1. Amplification from genomic DNA templates
    1. Thermocycler (amplification)
      1. Repeated heating and cooling (denaturation)
        Heating seperates
        Cooling binds
    2. Gel electrophoresis
      1. Agrose gel
        Seperated by weight
    3. Annealing step (binding process)
      1. Elongation step (Enzymatic replication / DNA polymerase)
        PCR then acts as a chain reaction and the DNA template is repeatedly amplified and replicated
2. Recombination
  1. Plasmids/phage used

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Genetics

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	Created by Arron Watson almost 9 years ago