DNA

• DNA is a polymer made of 2 strands coiled to form a double helix structure. The strands are linked by a series of complementary base pairs joined together by weak hydrogen bonds. DNA is made of nucleotides that are made up of a sugar and phosphate group with a base pair attached to the sugar.
• An organisms genome is its entire DNA.
• A gene is a section of a DNA molecule that codes for a specific protein.
• Extracting DNA from fruit:

  • Mash fruit and add to a beaker with detergent and salt - detergent breaks down cell membrane and release DNA, salt will stick it together
  • Filter mixture to separate big insoluble cell parts
  • Add ice-cold alcohol
  • DNA will float to the surface as a stringy white precipitate- its insoluble in cold alcohol