ch 12 – dna technology

8/3/2019 Ch 12 DNA Technology

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Fast moving organisms

What is the fastest land animal?


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Fastest in North America?


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Fastest flying bird?


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Spine tailed swift 106 mph


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Peregrine Falcon

Video


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Fastest biological acceleration?


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Artillery Fungus

180,000 gs, humans die at 50-100 gs, depending on force


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Morus alba

Petals move up to the speed of sound


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Ch 12 DNA Technology


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DNA Technology

Overview of current

methods of how we

use/ modify DNA

This lecture

probably outdated in

5-10 years


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Biotechnology

Manipulation of

organisms or their

components to make

useful products Not a new field

Selective breeding

Agriculture


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Biotechnology Today

Actually DNA

technology

Studying and

manipulating geneticmaterial

Recombinant DNA

DNA from 2 sources

Genetic engineering direct manipulation of

genes


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Genetically Modified Organisms

Organism that hasmodified genesthrough artificial

means Transgenic

organism with genesof another species

of all corn of all soybeans andcotton

Rice daffodil genesto increase nutrition


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Applications of Genetic

Engineering Diabetes Type I Pancreas doesnt

create insulin

B

ody cant absorbglucose

Body starves itself,even ifperson alwayseats

Old treatment Insulin from pigs and

cows

Many allergic reactions


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Diabetes

New treatment

1979 inserted human

insulin gene into

E. coli Extremely easy to

grow

1982 human insulin

available to USpopulation


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Other human proteins

Human Growth

Hormone (HGH)

Old treatment

Cadavers

Expensive and difficult

to extract

Now bacteria produce

HGH

Hepatitis B

Yeast cells make surface

proteins of virus

Allows immune system to

adapt to virus withoutactually being infected


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How to mass produce a protein

Bacteria

Well understood

Easy to grow

Quickly reproduce

Make own nutrients

Only need to add simple

growth media

Insert gene into bacteria

Let bacteria grow Isolate protein of interest


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Protein production

Plasmid small ringof DNA Separate from larger

bacterial chromosome Modifies only smallring, not entirechromosome

Replicates itself

Tiny extrachromosome


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How to cut DNA

Restriction enzyme

Cuts DNA at specific

sequences

i.e. - GAATTC

Matching ends of

DNA fragment can be

spliced with other

DNA


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Gel Electrophoresis

Method to compareDNA from 2 sources

Uses a porous gel

that DNA travels

through

DNA Negatively charged

Larger = slower

Same DNA will cut in

same spot = samepattern


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DNA Profiling

Compares DNA to

determine matches

Tissue collected

DNA isolated

DNA amplified

DNA cut at many

places

Gel Electrophoresis

Patterns compared


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Problems with DNA analyses

What if only a little

DNA is found?

DNA analysis requires

large amounts of DNA To get 2 mg of DNA

Requires about 1 lb of

tissue

How is DNA

amplified?


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Polymerase Chain Reaction

Method to amplify DNA

1. DNA is added to mixcontaining

Nucleotides

DNA polymerase

Few other ingredients

2. Mix heated separates strands

3. Mix cooled DNA polymerase buildsother strand

double strand reformed


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Human Genome Project

Human Genome

3.2 billion base pairs

18 stories of your

textbook 20,000 genes

Same # as roundworm

98% of it noncoding

Promoters

Enhancers

miRNAs

Introns

Most - unknown

purpose


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Human Gene Therapy

Adding normalcopies of a geneinto a mutants

genome Often doesntwork

Unforseen

consequences Gene is inserted

into patientsDNA randomlyby a virus


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Human Gene Therapy

Severe Combined

Immunodeficiency

Disease

Terminal disease

Bubble boy disease

22 people underwent

gene therepy

Removed immune

system cells Infected them with

harmless virus carrying

normal gene

Reinjected cells

4 developed leukemia

Virus activated oncogene

No control over where it

inserts DNA


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Ethics and Safety

Controversial topic

New GM crops banned inEurope

Fear over introduction ofgenes into wildpopulations

US Natl. Acad. ofSci. No evidence that

transgenic crops pose a

threat

20% of human genespatented

ch 12 – dna technology

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