Biotechnology………
the use and application of living things and
biological processes. Biotechnology is used
in medicine, agriculture, forensics, and
many other fields.
Biotechnology
In 2004, this child became known
as Baby 81 when disaster struck
his small village in Southeast
Asia. After a devastating
tsunami hit, he was rescued and
months later reunited him with
his biological parents.
How does a child’s DNA compare
with the DNA of his or her
parents?
How do you think biotechnology
is involved in Baby 81’s story?
Biotechnology
• DNA is far too small to see and
can not be manipulated by hand
• Biotechnology allows scientists
to work with DNA by the use of
chemicals, computers, and
bacteria (to name a few).
• Chemical mutagens are used to
change DNA sequences
• Computers analyze and organize
the vast amounts of data from
genetic research
• Bacterial enzymes are used it cut
and copy DNA
• Bacteria is also used to transfer
genes between organisms.
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Biotechnology
Bacterial enzymes are used to cut
DNA
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Why would scientists need
to cut DNA?
Bacteria cells can be infected by
viruses. As protection, bacteria
produces enzymes that cut up viral
DNA. This restricts the effect of
the virus on the bacterium.
Restrictive Enzymes: enzymes that
cut DNA molecules at a specific
nucleotide sequence
The restriction site is the
nucleotide sequence identified to
cut.
There are hundreds of restrictive
enzymes that have different
restriction sites.
Restrictive Enzymes
• Recognize nucleotide sequences that are between 4 and 8
base pairs long…then cut
• Some make straight cuts which leave “blunt ends” while
other make staggered cuts leaving “sticky ends”
• “Sticky Ends” are like velcro ready to hook on to their
opposite sites if base pairs are complementary
Biotechnology: Gel Electrophoresis
• Before cut DNA can be utilized,
the DNA fragments have to be
separated from one another.
• The fragments are sorted
according to size by a technique
called gel electrophoresis.
• Gel Electrophoresis: an electrical
current is used to separate a
mixture of DNA fragments from
each other.
• DNA fragments of different
sizes appear as different
bands or lines on the gel
• Restriction maps show the
lengths of DNA fragments
between restriction sites in a
strand of DNA
What do you think happened??
Suppose you cut DNA. You know that you should
find four DNA fragments on a gel, but only three
appear, and one fragment is very large. Explain
what happened.
Biotechnology: Copying DNA
• In order to get an amount of DNA that is large
enough to be studied, the DNA must be copied over
and over again.
• Polymerase Chain Reaction (PCR) is a process that
produces millions/billions of copies of a specific
DNA sequence in just a few hours.
• DNA polymerase has a key role in this process
Biotechnology: PCR Process
Requires 2 primers; primers are short segments of DNA that act as starting
points for a new strand. There are 3 main steps to PCR:
1) Separating: Using heat, the double strand of DNA is
separated into single strands
2) Binding: Primers bind to their complementary DNA
sequences
3) Copying: DNA polymerase build new strands of DNA.
Added nucleotides bind to the original DNA strands by
complementary base pairing. This continues until the
entire DNA segment has been copied
Each PCR cycle doubles the number of DNA copies. This
doubling is why PCR is referred to as a chain reaction.
Polymerase Chain Reaction
PCR Amplifies DNA Samples
Think About It………
Describe how heating double stranded DNA
separates the strands. Why does heating also
inactivate DNA polymerase from many organisms?
Biotechnology: DNA Fingerprinting
• Your complete set of DNA
(genome) is unique to you.
• DNA fingerprint: a
representation of parts of
individual’s DNA that can
be used to identify a
person at the molecular
level.
• A DNA fingerprint is a
specific type of restriction
map.
• DNA fingerprinting is used
for identification
Who committed the crime?
Cloning
• A clone is a genetically identical copy of
agene or of an organism. • Cloning allows scientists to
study using organs from cloned
mammals for transplant into
humans
•Cloning could help save
endangered species
• Success rate is low; takes
hundreds of tries to produce
one clone
•Clone typically is not as
healthy
•Reduces biodiversity
Genetic Engineering……….
the changing of an organism’s
DNA to give the organism new
traits
How is genetic
engineering possible
for ALL organisms?
Genetic Engineering
• Based on the use of
recombinant DNA
• Recombinant DNA: DNA that
contains genes from more than
one organism
• Bacteria are commonly used in
genetic engineering
• Bacteria have tiny rings of DNA
known as plasmids that are
separate the bacterial
chromosome. These plasmids
can replicate on their own.
Genetic Engineering
Bacteria with the recombinant plasmid are
called transgenic
• Transgenic: an organism that has one or
more genes from other organisms
• Ex; the gene for human insulin can be put in
to plasmids. The plasmids are inserted into the
bacteria . The transgenic bacteria make human
insulin that is collected and used to treat
people with diabetes.
•
Label the diagram below
Genetic Engineering…..Gene Knockout
• Gene knockout is type of gene manipulation that disrupts
the functioning of a gene
What is Genomics?
• Genomics is the study of genomes.
• A genome is all of an organism’s genetic material.
• All studies of genomes begin with gene sequencing; the order
of DNA nucleotides in a gene.
Human Genome Project
• Humans are estimated to
have between 30,000 and
40,000 genes
• Humans have at least 3 billion
DNA base pairs
• On average, one gene has
100,000 bases
• The Human Genome Project
has 2 goals: 1) map and
sequence all of the DNA base
pairs and 2) identify all of the
genes in a sequence
• Scientists accomplished the
first goal however continue to
work on the second
Genetic Screening and Gene Therapy
• Genetic Screening is
the process of testing
DNA to determine a
person’s risk of having
or passing on a genetic
disorder. It involves
both DNA and pedigree
analysis.
• Gene Therapy is the
replacement of a
defective or missing
gene, or the addition of
a new gene, into a
person’s genome to
treat a disease.
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