Transcript 13-2 Manipulating DNA - Pleasanton Unified School District

Chapter 13
Genetic Engineering
Section 13-2
Manipulating DNA
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Manipulating DNA
Key Concept:
Scientists Use Their
Knowledge Of The Structure
of DNA And Its Chemical
Properties To Study and Make
Changes To DNA Molecules
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Manipulating DNA
Key Concept (cont.)
Different Techniques are used to
Extract DNA from Cells, to Cut
DNA into Smaller Pieces, to
Identify the Sequence of Bases in
the DNA Molecule, and to Make
Unlimited Copies of DNA
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The Tools of Molecular Biology
Genetic Engineering
The Process of
Making Changes
In The DNA Code
of a Living Organism
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The Tools of Molecular Biology
DNA Extraction
Use Chemicals To Lyse Cells
Lysis:
a process of disintegration or
dissolution (as of cells)
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The Tools of Molecular Biology
Cutting DNA
DNA Too Large To Work With, So It
Is Cut Up Using:
Restriction Enzymes:
• They Are Very Precise
• 100’s Are Known
• Each One Cuts DNA At Specific Sequence of
Nucleotides
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Restriction Enzymes
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The Tools of Molecular Biology
Separating DNA
Gel Electrophoresis
• Mixture of Fragments Put In One
End of Gel
• Electric Voltage Applied
• Fragments Travel Toward Positive
End of Gel
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The Tools of Molecular Biology
Gel Electrophoresis (cont.)
–Smaller The Fragment, The
Faster It Moves
–Used To:
• Compare Genomes
• Locate Individual Genes
• Identify Base Pair Sequence
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Gel Electrophoresis
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Gel Electrophoresis
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Gel Electrophoresis
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Gel Electrophoresis
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Using The DNA Sequence
Once The DNA Is A
Manageable Size, You Can:
1. Read The Nucleotide
Sequences
2. Modify The Genome
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Using The DNA Sequence
Reading The Sequences
– Now Automated
– Small, Single Strands of DNA
– Add Enzyme That Makes
Complementary Strand
– Add Nucleotides, Some That Are
Labeled With A Specific Color of
Fluorescent Dye
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Using The DNA Sequence
FOOTHILL HIGH SCHOOL SCIENCE DEPARTMENT
Using The DNA Sequence
FOOTHILL HIGH SCHOOL SCIENCE DEPARTMENT
Using The DNA Sequence
Reading The Sequences (cont.)
–Addition of a Labeled Base To
Strand Terminates Replication
–Produces Multiple, Labeled
Strands of Different Lengths
–Each Terminal Base Is Color
Coded
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Using The DNA Sequence
Reading The Sequences (cont.)
–Separate by Electrophoresis
–Read The Base Sequences In
Order, By Color Codes
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Using The DNA Sequence
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Automated Sequencing
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Changing The DNA Sequence
Cutting & Pasting
You Can Take A Gene From
One Organism & Attach It To
The Gene of Another
Organism
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Changing The DNA Sequence
Cutting & Pasting (cont.)
Mixing Genes From Different
Organisms Results In
Recombinant DNA
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Using The DNA Sequence
Making Copies
PCR = Polymerase Chain Reaction
Quickly Makes Multiple
Copies Of Small DNA
Targets
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PCR
Polymerase Chain Reaction
Add Short Strand of Complementary
DNA To Each End Of The DNA You
Want To Copy
Primers
Provide Location For DNA
Polymerase To Attach
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PCR
Polymerase Chain Reaction
• Heat To Separate The Strands Of DNA
• Cool To Allow Primers To Attach The
Primers
• Increase Temperature To Activate TAQ
Polymerase (High Temperature DNA
Polymerase)
• Repeat 20 – 30 Times
– Copies Also Act As Templates
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PCR
Polymerase Chain Reaction
Within A Few Hours You Will Have
Millions of Copies
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PCR
Polymerase Chain Reaction
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PCR
Polymerase Chain Reaction
• Kary Mullis
– Invented PCR
– Source of High
Temperature DNA
Polymerase
(taq Polymerase)
• Bacteria In hot
springs of
Yellowstone Park
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PCR
Polymerase Chain Reaction
Yellowstone Hotspring
Source of High Temperature PCR DNA Polymerase
(taq Polymerase)
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