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Wed 3.6.2013

Wed 3.6.2013

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Wed 3.6.2013

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  1. Wed 3.6.2013 • Today’s Objectives(Write on today’s NOTES!) • Review the structure & function of DNA • Prepare for the DNA extraction lab

  2. TAKE NOTES! Nucleus; in eukaryotes Double Helix 4 base pairs (A,C,G,T) Chromatin which condenses into chromosomes

  3. Cell wall (only in plants) 2. Nuclear Membrane 3. Cell Membrane

  4. To extract the DNA ….. Which parts of the cell do you have to go through to remove the DNA? BARRIERS TO OVERCOME BARRIER 1: Cell Wall (only in plant) BARRIER 2: Cell membrane BARRIER 3: Nuclear membrane

  5. BARRIER 1 - Cell Wall EXTRACTION PROCEDURE ACTIVITY FUNCTION Mashing/Crushing This breaks open the cell (LYSE) wall, cell membrane, and the nuclear envelope to allow the DNA to be released.

  6. Breaks open the cell wall

  7. BARRIER 2 – Cell Membrane&BARRIER 3- Nuclear Membrane EXTRACTION PROCEDURE ACTIVITY FUNCTION Detergent (buffer) Breakdownthe fat and proteins that make up the cell and nuclear membrane. (Just like the detergent dissolves grease on your dishes).

  8. Cell Membrane What components make up the membrane that surrounds the cell? REMEMBER Cell membranes are made ofphospholipids

  9. Cell Membrane Phospholipids are bi-layer, with a head and a tail. the head –LOVES WATER the tail – HATES WATER Phospholipids won’t dissolve in water HATES Water: HYDROPHOBIC LOVES Water: HYDROPHILIC

  10. Why am I adding Detergent?

  11. Breaks open the cell Breaks open the cell membrane and nuclear membrane

  12. Protein wrapped around DNA EXTRACTION PROCEDURE ACTIVITY FUNCTION Meat tenderizer (Enzyme) Adding an enzyme, such as meat tenderizer will break down proteins such as nucleases and histones that are wound around the DNA.

  13. Breaks open the cell Breaks open the cell membrane and nuclear membrane To cut proteins away from the DNA

  14. Filter EXTRACTION PROCEDURE ACTIVITY FUNCTION Filter Separate the components of the cell

  15. Breaks open the cell Breaks open the cell membrane and nuclear membrane To cut proteins away from the DNA Organelles, broken cell wall, membranes from proteins, carbohydrates

  16. Last Step! EXTRACTION PROCEDURE ACTIVITY FUNCTION • Alcohol DNA does not dissolve in alcohol. (It is soluble in water). The addition of alcohol causes the DNA to precipitate.

  17. Cold slows down molecules helping them clump together Alcohol is a weak polar solvent—causing insoluble DNA to separate out

  18. DNA Extraction Protocol DNA eNzymes (meat tenderizer) Alcohol Detergent Dissolve cell membranes Break down proteins Precipitate DNA Just follow these 3 easy steps: