DNA Structure

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DNA Structure

• Forensics
• Chp. 12
• DNA Analysis

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DNA Structure

• A gene is a long section of a DNA molecule whose
  sequence of building blocks specifies the
  sequence of amino acids in a particular protein.
• Protein- fundamental component of living cells
• Enzymes
• Hormones
• Antibodies

• Hemoglobin
• Insulin

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How does DNA work

• DNA (nucleic acid) ?
• Amino Acids ?
• Protein ? Do a job (perform a function)
• Analogy to remember whats going on, build a
  house
• DNA is the blue prints (instructions)
• Amino Acids are the lumber
• Proteins are the house

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DNA Structure

• View from the side - Helix
• Partially unwound double helix so you can see
  components

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Views from the top
Model
X-Ray
Photo-51
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• DNA composed of nucleotides
• Sugar (deoxyribose)
• Phosphate group
• Nitrogenous bases
• A - T
• C - G

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DNA Structure

• A 5 C sugar and a phosphate group form the
  backbone

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DNA Structure

• Nitrogenous bases
• A, T, C, G
• make up the rungs on the ladder

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Complimentary Base Pairing

• Bases held together with Hydrogen bonds
• Guanine pairs with Cytosine
• Triple bond
• Adenine pairs with Thymine
• Double bond

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DNA Structure
3D Video Clip (Click next 4 times)
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3 methods to analyze DNA

• RFLP- Restriction Fragment Lengths Polymorphism
• Restriction enzymes cut DNA up
• Not best method because we need a lot of DNA
• PCR Polymerase Chain Reaction
• Polymerase enzyme that replicates (makes more)
  DNA
• STR Short Tandem Repeats
• Specific sequences of DNA fragments that are
  repeated at a particular site on a chromosome

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Replication Technology

• Mitochondrial DNA- from mom only
• good for hair, teeth, and bone
• PCR-
• Perhaps the most successful technology to ever
  emerge from LIFE SCIENCE!!!
• Many Uses
• Forensics-
• blood, convict, exonerate false accusations
• Agriculture, Vet., Medicine, Env. Sci.,
• Microorganisms, viruses, parasites