Download DNA Manipulation

Manipulating DNA
Chapter 9
SC.912.L.16.10 – Students understand
the effect of biotechnology on the
individual, society, and the
environment.
DNA is way too small to cut with a razor, knife, or pair
of scissors.
This is why restriction enzymes must be used.
Restriction enzymes cut DNA at specific nucleotide
sequences.
The DNA fragments must be sorted according to size.
In gel electrophoresis, an electrical current is used to
separate DNA fragments from each other.
Restriction maps show the lengths of DNA fragments
between restriction sites in a strand of DNA.
How do scientists get an amount of DNA that is large
enough to be studied?
Polymerase Chain Reaction (PCR) is a technique tht
produces millions of copies of a specific DNA
sequence in a few hours.
Instead of using helicase to unwind the DNA, PCR uses
heat to separate the strands and then copies of each
strand are made.
Primer – short strand of DNA that acts as a starting
point for a new strand.
Unless you have an identical twin, your complete set
of DNA is unique to you.
Each person has a DNA fingerprint – a representation
of parts of an individual’s DNA that can be used to
identify a person at the molecular level.
A clone is a genetically identical copy of a gene or
organism.
Examples: bacteria, identical twins, sea stars, and
some plants such as banana plants.
Genetic engineering – changing an organism’s DNA to
give the organism new traits.
Genetic Engineering is based on recombinant DNA –
DNA that contains genes from more than one
organism.
Bacteria contain plasmids – tiny loops of DNA that are
separate from DNA within chromosomes. Plasmids
also replicate on their own.
Scientists can add genes to a plasmid and place that
plasmid inside of a bacterium.
Bacteria with added plasmids are called transgenic
bacteria. They will express the genes on that added
plasmid.
A transgenic organism has genes from another
organism inserted into it.
Transgenic bacteria are used to produced insulin for
people with diabetes.
This is one way that genetic engineering has helped
improve health and society.
Transgenic plants with pesticide genes can be grown
more quickly to feed more people.
This is another way that genetic engineering has
helped decrease famine and improve health.
Some concerns about genetically modified foods
include:
- Could some produce allergic reactions?
- Is it ethical to change the genes of an organism?
- What would happen if these genes got into the
“wrong” organisms?
- Could making these foods decrease biodiversity?
A genome is all of an organism's genetic information.
Genomics is the study of genomes within humans and
other organims.
Gene sequencing is determining the order of
nucleotides in DNA.
Recall that the order of nucleotides within DNA
determines the protein that will be translated.
The human genome has approximately ~
3 billion basepairs and 30,000 to 40,000 genes.
Recall that a base pair is when one nucleotide forms a
hydrogen bond with another. A-T, G-C, etcetera.
The Human Genome Project has the goals of 1)
mapping and sequencing all of the DNA basepairs 2)
identify ALL genes within the sequence.
Bioinformatics is the use of computer databases to
organize biological data.
Proteomics is the study of all the proteins that result
from an organism’s genome.
Recall that proteins are the result of DNA translation.
Some people have a higher risk of developing a
particular disease because of their genes.
We say that these people are genetically predisposed
for the disease.
Genetic Screening is the process of testing DNA to
determine a person’s risk of having or passing on a
genetic disorder.
Gene Therapy is the replacement of a defective gene
or the addition of a gene to treat a genetic disease.