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DNA and Genes

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DNA and Genes Modified Chapters 10, 11, & 12 DNA verse RNA .Review DNA and RNA are nucleic acids DNA genetic information RNA used to build proteins Built by ... – PowerPoint PPT presentation

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Title: DNA and Genes


1
DNA and Genes
  • Modified Chapters 10, 11, 12

2
DNA verse RNA.Review
  • DNA and RNA are nucleic acids
  • DNA genetic information
  • RNA used to build proteins
  • Built by nucleotides
  • Can be single stranded or double stranded
  • Bases
  • Bonds

3
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4
DNA verse Gene??
  • DNA
  • Nucleic acid
  • Comprised of chromosomes
  • Every person genetically unique
  • Gene
  • Segment of DNA
  • Carries instructions for products to be made
  • Every person has same genes, but each varies

5
DNA Replication
  • Complete set of genetic instructions must pass
    from one generation to the next
  • Begins at specific sites on a double helix
  • Proceeds in both directions

6
Overview
1. Strands separate a. New nucleotides
b. Result 2 DNA copies, each 1 new 1
old chain 2. DNA polymerase 3. Leading strand 4.
Lagging strand 5. Primer
7
Flow of Genetic Information from DNA to RNA to
Protein
  • Information contained in DNA is stored in blocks
    called genes
  • genes code for proteins
  • proteins determine what a cell will be like
  • DNA stores information in nucleus
  • instructions are copied from the DNA into
    messages comprised of RNA
  • these messages are sent out into the cell
  • direct the assembly of proteins

8
Flow of Genetic Information from DNA to RNA to
Protein
  • The path of information is often referred to as
    the central dogma
  • DNA ? RNA ? protein
  • Gene expression
  • Transcription
  • messenger RNA (mRNA) made from a gene within the
    DNA
  • Translation
  • Using the mRNA to direct the production of a
    protein

9
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10
Transcription
  • First step
  • Occurs in nucleus
  • Genetic information transferred from DNA to RNA
  • Important players
  • RNA polymerase
  • Ribosomal RNA (rRNA)
  • Introns removed
  • Exons spliced together

11
Translation
  • Second step
  • Occurs in cytoplasm
  • Conversion from the nucleic acid language to the
    protein language
  • Important players
  • Messenger RNA (mRNA)
  • mRNA is read in three-nucleotide units called
    codons
  • Transfer RNA (tRNA)

12
The genetic code (RNA codons)
There are 64 different codons in the genetic
code!!!!
13
Genes gone bad
  • Mutation
  • Any change in the nucleotide sequence of DNA
  • Can result in changes in the amino acids in
    proteins
  • Often harmful, but are they always??
  • Mutations may result from
  • Errors in DNA replication
  • Physical or chemical agents called mutagens

14
How are Genes Regulated??
  • In cellular differentiation
  • Certain genes turned on and off
  • Cells become specialized in structure and
    function
  • In gene expression
  • A gene is turned on and transcribed into RNA
  • Information flows from genes to proteins,
    genotype to phenotype

15
DNA TECHNOLOGY
16
How do we use DNA to our advantage???
  • Cloning
  • Recombinant DNA
  • GMO

17
Cloning Plants and Animals
  • Nuclear transplantation
  • Involves replacing nuclei of egg cells with
    nuclei from differentiated cells
  • Has been used to clone a variety of animals
  • Scottish researchers cloned the first mammal in
    1997
  • Dolly!!
  • Reproductive cloning

18
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19
Recombinant DNA Technology
  • Set of techniques for combining genes from
    different sources into a single DNA molecule
  • genetically modified (GM) organism
  • organism that carries recombinant DNA
  • Recombinant DNA technology is applied in the
    field of biotechnology
  • Biotechnology uses various organisms to perform
    practical tasks

20
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21
Genetically Modified (GM) Foods
  • Replacing traditional plant-breeding programs
  • Corn has been genetically modified to resist
    insect infestation

22
Recombinant DNA Techniques
  • Bacteria.
  • To work with genes in the laboratory, biologists
    often use bacterial plasmids
  • Small, circular DNA molecules

23
Recombinant DNA Techniques
  • Plasmids
  • Can easily incorporate foreign DNA
  • Readily taken up by bacterial cells
  • Act as vectors
  • DNA carriers that move genes from one cell to
    another
  • Can help biologists produce large quantities of a
    desired protein

24
Cutting and Pasting DNA with Restriction Enzymes
  • To combine the plasmid and gene
  • piece of DNA must be spliced into a plasmid
  • Accomplished using restriction enzymes
  • cut DNA at specific nucleotide sequences
  • cuts produce pieces of DNA called restriction
    fragments
  • May have sticky ends that are important for
    joining DNA from different sources

25
Transformation of Insulin Gene
  • human insulin gene isolated and cut from its
    location on the human chromosome
  • using a restriction enzyme
  • plasmid is cut using the same restriction enzyme
  • desired DNA (insulin gene) and plasmid DNA can be
    joined using DNA ligase
  • plasmid now contains the genetic instructions on
    how to produce the protein insulin
  • Bacteria can be artificially induced to take up
    the recombinant DNA plasmids and be transformed
  • successfully transformed bacteria will contain
    the desired insulin gene
  • transformed bacteria containing the insulin gene
    can be isolated and grown
  • As transformed bacteria grow they will produce
    the insulin proteins coded for the recombinant
    DNA
  • Insulin harvested and used to treat diabetes

26
DNA Fingerprinting and Forensic Science
  • DNA technology has rapidly revolutionized the
    field of forensics
  • scientific analysis of evidence from crime scenes
  • Uses
  • Paternity
  • Victim identification
  • Crimes
  • Evolutionary research
  • Study ancient pieces of DNA
  • Cheddar Man!!!!

27
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28
Tracking the Anthrax Killer
  • In October 2001, Florida man died from inhalation
    anthrax
  • By the end of the year, four other people had
    also died from anthrax
  • Investigators analyzed the genome of the anthrax
    spores used in each attack
  • Able to establish that the spores from all of the
    cases were identical
  • Suggested a single perpetrator of the crime
  • Able to match the anthrax with one laboratory
    subtype
  • The Ames strain

29
Conviction
  • Betty Anne Waters
  • Ayer, MA
  • 1982 brother arrested for murder
  • Waters went to CCRI
  • GED
  • Associates
  • Went to Roger Williams to get Bachelors and Law
    degree
  • Became brothers lawyer
  • Witnesses lied
  • DNA evidence in 1990s
  • Innocence Project
  • Released in 2001 after serving 18 years in prison
  • 3.4 million dollar settlement

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