Today - PowerPoint PPT Presentation

1 / 80
About This Presentation
Title:

Today

Description:

Today s Agenda: Journal Questions: (1) Describe what you know about DNA. (2) What is genetic engineering (Biotechnology)? *1. Lecture: Genetic Engineering ... – PowerPoint PPT presentation

Number of Views:142
Avg rating:3.0/5.0
Slides: 81
Provided by: RickWo2
Category:

less

Transcript and Presenter's Notes

Title: Today


1
Today s Agenda
  • Journal Questions
  • (1) Describe what you know about DNA.
  • (2) What is genetic engineering (Biotechnology)?
  • 1. Lecture Genetic Engineering (Biotechnology)
    Recombinant DNA Technology -slide . 80

2
Genetically Modified (GM) Crops around the World
3
(No Transcript)
4
(No Transcript)
5
Genetic Engineering
  • Dr. Rick Woodward

6
Genetic Engineering
7
Genetic Engineering
8
Genetically Engineered Boneless Chicken Ranch
9
DNA, the Law, and Many Other Applications The
Technology of DNA Fingerprinting
A DNA fingerprint used in a murder case.
The defendant stated that the blood on his
clothing was not his.
What are we looking at? How was it produced?
10
DNA Fingerprinting Basics
A. Different individuals carry different alleles.
B. Most alleles useful for DNA fingerprinting
differ on the basis of the number of repetitive
DNA sequences they contain.
11
DNA Fingerprinting Basics
A DNA fingerprint is made by analyzing the sizes
of DNA fragments produced from a number of
different sites in the genome that vary in
length.
12
The DNA Fragments Are Separated on the Basis of
Size
The technique is gel electrophoresis.
The pattern of DNA bands is compared between each
sample loaded on the gel.
13
Gel Electophoresis
  • A. Technique used to separate nucleic acids or
    proteins by size and charge.

14
California Biology Content Standards
  • California Content Standards
  • 5 b. Students know how to apply base-pairing
    rules to explain precise copying of DNA.
  • 5 c. Students know how genetic engineering
    (biotechnology) is used to produce novel
    biomedical and agricultural products.
  • 5 e. Students know how exogenous DNA can be
    inserted into bacterial cells to alter their
    genetic makeup and support expression of new
    protein products.

15
DNA Review
  • A. Structure Double Helix
  • B. Location Nucleus of Cell
  • C. Function Blue print of Life Creation of
    Proteins/Amino Acids Transcription.
  • D. Nitrogen Base ATCG
  • E. Nucleotide Phosphate, Sugar (Deoxyribose),
    Nitrogen Base (ATCG).
  • F. Base Pairing Rules A-T
  • C-G

16
Genetically Modified (GM) Food
Genetically Modified Cotton (contains a
bacterial gene for pest resistance)
Standard Cotton
17
Genetically Modified (GM) Food
18
What is Genetic Engineering?
  • Genetic engineering is the technology for
    modifying the genetic information in a plant,
    animal or human in order to produce some desired
    trait or characteristic

19
Genetic Engineering Vocabulary
  • A. Restriction Enzymes molecular scissors are
    enzymes that cut DNA only at particular
    sequences.
  • B. Plasmids are small circles of DNA found in
    bacteria.
  • C. Plasmids are used to replicate a recombinant
    DNA.
  • D. Vector - A vector is a small piece of DNA used
    to carry a gene of interest.

20
Genetic Engineering Recombinant DNA Technology
21
Restriction Enzymes are Enzymes that Cut DNA Only
at Particular Sequences
Different restriction enzymes have different
recognition sequences.
22
DNA Cut by a Restriction EnzymesCan be Joined
Together in New Ways
These are recombinant DNAs and they often are
made of DNAs from different organisms.
23
Plasmids are Used to Replicate a Recombinant DNA
A. Plasmids are small circles of DNA found in
bacteria.
B. Plasmids replicate independently of the
bacterial chromosome.
24
Human Insulin Production by Bacteria
  • 1. Isolate human cells and grow them in tissue
    culture.
  • 2. Isolate DNA from the human cells.
  • 3. Isolate plasmid DNA from a bacterium.
  • 4. Use the same restriction enzyme to cut the
    plasmid DNA.
  • 5. Mix the recombinant plasmid with bacteria.
  • 6. Allow the new bacteria to incorporate the
    recombinant plasmid into the bacterial cell.
  • 7. Grow trillions of new insulin producing
    bacteria (this is when cloning takes place).
  • 8. A fermentor is used to grow recombinant
    bacteria.
  • 9. Collect the bacteria, break open the cells
    and purify the insulin protein.

25
Harnessing the Power of Recombinant DNA
Technology Human Insulin Production by Bacteria
26
Human Insulin Production by Bacteria
27
Human Insulin Production by Bacteria
Screening bacterial cells to learn which contain
the human insulin gene is the hard part.
28
Route to the Production by Bacteria of Human
Insulin
This is the step when gene cloning takes place.
The single recombinant plasmid replicates within
a cell.
29
Route to the Production by Bacteria of Human
Insulin
The final steps are to collect the bacteria,
break open the cells, and purify the insulin
protein expressed from the recombinant human
insulin gene.
30
Overview of gene cloning.
Route to the Production by Bacteria of Human
Insulin.
31
Genetic Engineering Insulin Production Overview
32
Monday (March 12, 2012)Genetic Engineering
  • Journal Question What is a plasmid?
  • 1. Lecture II Genetic Engineering
  • 2. Comprehensive Exam next Monday.

33
Reviewing Genetic Engineering
34
Banking Genes
  • A. The massive Svalbard Global Seed Vault is
    built into the permafrost deep in a mountain on a
    remote arctic island in Norway

35
Banking on Genes
  • B. Built in 2008
  • After receiving its first deposits, a
    doomsday seed vault on an Arctic island has
    amassed half a million seed samples, making it
    the worlds most diverse repository of crop
    seeds.

36
Most Widely Used Genetically Modified Crops are
  • 1. Cotton plants with a built-in resistance to
    insects.

37
Most Widely Used Genetically Modified Crops are
  • 2. Corn and Soybeans resistant to the herbicide
    Roundup.
  • a. Allowing Farmers to employ no-till
    techniques to farming.

38
Which country is the leader in plant
biotechnology?
  • Answer China
  • A. They have recently sequenced the rice genome.

39
Problems with Genetic Engineering Technology
  • 1. Environmental Problems
  • 2. Food Safety
  • 3. Access to the New Techniques

40
Environmental Problems
  • A. Pest resistant properties of transgenic
    crops.
  • B. If pests have a broad exposure to the toxin
    or some other resistance incorporated into the
    plant, it is possible that they will develop
    resistance to the toxin and thus render it
    ineffective as an independent pesticide.

41
Food Safety
  • A. Food safety issues arise because transgenic
    crops contain proteins from different organisms
    and could trigger an unexpected allergic response
    to people who consume the food.

42
Access to the New Techniques
  • A. Relates to the developing world.
  • B. Farmers in the developing countries are
    unable to afford the higher cost of the new
    genetically altered seeds.

43
Other Types of Genetic Engineering
  • 1. Transgenic Engineering
  • a. Putting genetic information from one type of
    plant or animal into another.
  • 2. Cloning
  • a. Making exact genetic copies of an existing
    plant or animal.

44
Transgenic Organisms
  • A. An organism is called transgenic if it has
    genetic information added to it from a different
    type of organism.
  • B. Viruses do something of this sort when they
    infect plants, animals or humans.
  • C. Humans have begun to do this with plants and
    animals.

45
Transgenic Organisms
  • D. This is the work that is furthest along
  • (1) Corn with its own insecticide.
  • (2) Soybeans cotton resistant to
  • herbicides.
  • (3) Papayas resistant to viruses

46
Transgenic Organisms
  • F. Human genes have been inserted into
  • (1) Bacteria (Prokaryotes)
  • (2) Mice
  • G. To produce various human proteins for
    treating diseases.

47
Making Transgenic Mice
48
Advantages of Transgenic Organisms
  • A. Plants
  • (1) More disease-resistant.
  • (2) Larger yields.
  • (3) More transportable.
  • B. Animals
  • (1) Make proteins for medicinal purposes.
  • (2) Make organs for transplant to humans.

49
Cloning Exact Copies
  • A. A clone is an exact copy.
  • B. In genetics, a clone is a genetic copy of
    another organism.
  • C. Clones occur naturally
  • Asexual breeding in plants lower animals
  • Identical twins (triplets) in higher animals
  • D. For centuries it has been known that simple
    animals worms starfish can be cloned by
    cutting them in half.
  • E. This doesnt work for higher animals!
  • F. Part of the problem is cell specialization
  • Nerve, Bone, Muscle, etc.

50
Cloning in the 20th Century
  • A. We now realize that each specialized cell has
    all the genetic information, but much of it is
    turned off.
  • B. Problem how to reset the program
  • so this information is usable?
  • C. Cloning of frogs successful in 1950s
  • D. Cloning of livestock from fetal cells in
    1970s.

51
Cloning in the 20th Century
  • E. The human genome (an organisms genetic
    material) consists of 3 billion base pairs of DNA
    and about 30,000 genes.
  • (1) 97 of our DNA does not code for protein
    product.
  • -mostly consisting of repetitive sequences that
    never get transcribed.

52
Cloning in the 20th Century Hello Dolly
  • F. Clone from an adult sheep cell by Scots
    researchers under Ian Wilmut.
  • G. Had only one success in 300 attempts.
  • H. Dolly grew to maturity, and successfully
  • had a lamb by natural means in 1998.
  • I. But Dolly seems to be prematurely old.

53
Cloning
54
Cloning
55
Genetic Engineering
  • Genetic engineering (also known as genetic
    manipulation or GM) is not the same as cloning.
  • -Though cloning techniques are used in genetic
    engineering, the two processes should not be
    confused.

56
Genetic Engineering versus Cloning
  • A. Cloning
  • 1. Produces exact copies
  • 2. Genes replicated within the
  • same species.
  • B. Genetic Engineering
  • 1. Produces a totally unique
  • set of genes.
  • 2. Genes can be swapped across species.

57
Selective Breeding versus Genetic Engineering
  • A. In the past, humans have brought about change
    in the genetic make-up of organisms by means of
    selective breeding (artificial selection) i.e.
    Purebreds
  • B. Genetic engineering brings about such change
    by scientifically altering an organism's genetic
    code.

58
Genetic Engineering Overview
  • 1. In genetic engineering enzymes are used to
    cut up and join together parts of the DNA of one
    organism, and insert them into the DNA of another
    organism.
  • 2. In the resulting new organism the inserted
    genes will code for one or more new
    characteristics - for example producing a new
    substance, or performing a new function. The
    organism has been genetically re-engineered

59
Other names for Genetic Engineering
  • A. This technique is also known as gene splicing
    or recombinant DNA technology (because the DNA is
    recombined in the vector molecule.
  • B. Vector - A vector is a small piece of DNA
    used to carry a gene of interest. Besides the
    gene being studied, a vector may contain elements
    which are used to help the gene integrate into a
    genome.

60
Why does genetic engineering work?
  • A. Genetic engineering works because there is
    only one code for life. The set of instructions
    for which a gene is responsible work whichever
    organism the gene is in, and whatever
    instructions that gene gives are carried out
    within the cells of the recipient.
  • B. Theoretically the possibilities are limitless,
    although this sort of manipulation gives rise to
    strong feelings for and against.

61
Applications of Genetic Engineering
  • A. One field in which genetic engineering has
    had a huge impact is the mass production of
    insulin to help diabetics. Scientists have
    isolated the gene responsible for making human
    proteins, including the insulin hormone. This
    gene is inserted into the bacterial DNA, and the
    microbes then clone themselves rapidly, making
    identical copies of themselves, all with the new
    gene and all capable of making human insulin.
  • B. This is a cheap way of producing sufficient
    quantities of exactly the right hormone, for
    everyone who needs it.

62
Other Applications of Genetic Engineering
  • C. Producing interferon, a human protein which
    stops viruses multiplying inside the body.
  • D. Producing human growth hormone to treat growth
    abnormalities
  • E. Blood clotting factor to treat hemophiliacs.
  • F. Used in industry to produce enzymes for use
    in biological washing powder.
  • G. Producing pest resistant crop varieties.
  • H. Producing tomatoes and other produce that
    stay fresh much longer.

63
Introduction to Genetic Engineering
  • 1. With genetic engineering scientists directly
    manipulate genes.
  • a. It frequently involves the use of recombinant
    DNA, which is composed of DNA segments from at
    least two different organisms.

64
Commercial Applications
  • 1. An example is the use of recombinant DNA
    technology to make interferon, a virus-destroying
    protein naturally produced by the human body.

65
Production of Synthetic Interferon Involves
  • 1. Isolating the human gene that codes for the
    interferon production.
  • 2. Splicing this gene into a strand of bacterial
    DNA.
  • 3. Inserting recombinant DNA into a bacterium.
  • 4. Cloning the bacterium and collecting the
    product Interferon.

66
Isolation of a Gene
  • A. The first step in the process is isolating
    the human interferon gene.
  • B. Genetic engineers use restriction enzymes,
    proteins that cut a DNA molecule into pieces.

67
Isolation of a Gene
  • C. The restriction enzyme EcoRI cuts DNA wherever
    the sequence C-T-T-A-A-G occurs.
  • D. Other restriction enzymes cut DNA at different
    nucleotide sequences.
  • E. By using the proper restriction enzymes
    scientists can cut the human interferon gene out
    of its chromosome.

68
Gene Splicing
69
Isolation of a Gene
  • F. Once the gene for interferon is removed, it is
    separated from the rest of the DNA and then
    inserted into a strand of bacterial DNA.

70
Gene Splicing
  • A. Gene splicing is the process by which a gene
    from one organism is placed into the DNA of
    another organism.
  • B. The human interferon gene is placed into the
    DNA of E. coli, the common bacterium of the human
    intestine.

71
Gene Splicing
  • C. In addition to a single, circular chromosome,
    E. coli contains a single, small ring of DNA
    called a plasmid.
  • (Plasmid a single ring of DNA in bacteria)
  • D. Human DNA is inserted into this plasmid.

72
Gene Splicing
  • E. The plasmid ring is removed from the bacterium
    and the opened with a restriction enzyme.
  • F. The human interferon gene and the bacterial
    plasmid have sticky ends unpaired bases at
    each end of the DNA segment, where they were
    cleaved by restriction enzymes.

73
Gene Splicing
  • G. As the human DNA is spliced into the plasmid
    DNA, the unpaired bases of each bond readily.
  • H. Consequently, a newly formed plasmid contains
    both human and bacterial DNA.

74
Insertion, Cloning, and Collecting
  • A. Once a DNA fragment is incorporated into a
    plasmid, the plasmid is inserted into another
    bacterium, which is then placed in a culture
    medium, where it divides and replicates.

75
Insertion, Cloning, and Collecting
  • B. Each time a bacterium divides a new copy of
    the plasmid DNA, which includes the human DNA
    gene, is created.
  • C. This process by which the human gene is
    replicated is called gene cloning

76
Insertion, Cloning, and Collecting
  • D. Because E. coli can divide every 20 minutes,
    gene cloning is an efficient way to produce many
    copies of a specific genetic sequence.

77
Insertion, Cloning, and Collecting
  • E. The gene for human interferon is thus
    expressed in bacterial cultures and the resulting
    interferon protein is collected and eventually
    used by physicians.

78
(No Transcript)
79
(No Transcript)
80
Genetically Modified (GM) Crops
  • The ear of genetically engineered corn at top
    contains a toxin that kills worms.
Write a Comment
User Comments (0)
About PowerShow.com