DNA and Genes

• dna stands for deoxyribonucleic acid, it contains all the instructions needed to make an organism
• Genome: genetic information
• Nucleic Acids

  • base units are nucleotides
  • made up of phosphate group, sugar molecules, nitrogen base
• X-ray diffraction of DNA

  Taken by Rosalind Franklin

  
• First DNA model structure

  • Watson and Crick

  
• DNA Structure: Double helix, 2 strands of nucleotides, Rungs (4 bases per strand), Backbones (alternating sugar and phosphate)
• DNA replication Process:

  1. DNA untwists with the help of Gyrase (hydrogen bonds break)
  2. The ladder unzips with DNA Helicase (parent strands always remain intact
  3. Free floating nucleotides attach to parent strands with DNA polymerase
  4. DNA ligase is the glue that binds the backbone back together
• DNA untwists with the help of gyrase

  
• Ladder unzips

  
• Free floating Nucleotides attach to parent strands with the help of DNA Polymerase

  
• DNA ligase glues strands back together

  
• Semi conservative: the new strands of DNA are made up of 1/2 of old nucleotides (from the parent) and 1/2 of new nucleotides
• Proteins (amino acids):

  • chemicals that make up a cell structure
  • make up the cell membrane and organelles
  • make up the muscle filaments that enable movement
  • produce enzymes, antibodies and hormones
• Codon: A sequence of three nucleotides that codes for a specific amino acid.
• mRNA:

  • carrier molecules that are formed from the DNA code by RNA polymerase
  • carriers the message to the ribosome to make proteins
• mRNA process:

  1. Initiator codon (AUG) on mRNA is formed from DNA
  2. mRNA is transcribed from complementary DNA strand
  3. Terminator codon (UAA, UAG, UGA) stops the production
• Translation: The process of converting the information in a gene into a sequence of amino acids.
• Translation process:

  1. mRNA with the codons exits the nucleus and into cytoplams
  2. Attaches to a ribosome
  3. the initiator codon turns on protein synthesis
  4. Transfer RNA, tRNA, is created and picks up amino acids in the cytoplasm and moves them to the ribosome complex
  5. mRNA strand that is attached to ribosome will select the proper tRNA based on the anticodons
  6. tRNA leaves the amino acid and looks for a new one
• Mitochondrial DNA: 100% comes from the mom, 0% from the dad
• Genetic modification: The process of introducing a gene from one organism into another organism.
• Restriction enzyme: An enzyme that cuts DNA at specific sequences.
• Recombinant DNA process:

  1. Restriction enzyme cuts the gene of interest
  2. restriction enzyme cuts DNA to insert new gene
  3. ligase glues in new gene
• Polymerase Chain Reaction (PCR): the photocopiers for DNA
• Gel Electrophoresis: separates DNA fragments based on size and charge.
• DNA profiling: a technique used to compare DNA from a suspect to DNA from a database of known offenders
• Viral vectors: vectors that contain a gene of interest and are used to deliver genes into cells
• Mutations: A change in the DNA sequence of an organism that can lead to a change in the phenotype (Harmful, neutral, useful)
• Radiation: The transfer of energy in the form of electromagnetic waves, such as light, radio waves, and gamma rays.
• Frame shift mutation:

  
• Point mutation: the fat cat ate the hot dog


  the fat car at the hot dog
• Frameshift deletion: the fat ca_ ate the hot dog


  the fat caat tet heh otd og
• Frameshift addition: the fat cat date the hot dog


  the fat cat date eth eth eho tdo g
• Point mutation: