Download Biotechnology

DNA Technology
What is biotechnology?

Biotechnology = bios (life) + logos
(study of)

Literally ‘the study of tools from
living things’
What is biotechnology?
• Biotechnology:
is the process of harnessing 'nature's own'
biochemical tools to make possible new
products and processes and provide
solutions to society's ills
What is biotechnology?
• Using scientific methods with organisms to
produce new products or new forms of
organisms
• Any technique that uses living organisms
or substances from those organisms or
substances from those organisms to make
or modify a product, to improve plants or
animals, or to develop microorganisms for
specific uses
Stages of Biotechnology
• Ancient Biotechnology
• early history as related to food and shelter,
including domestication
• Classical Biotechnology
• built on ancient biotechnology
• fermentation promoted food production
• medicine
• Modern Biotechnology
• manipulates genetic information in organism
• genetic engineering
Human Genome Project (HGP)
1.) HGP = Map of all 30,000 genes on the 46
human chromosomes (1988-2003)

Information has led to many advances in the
fields of medicine, agriculture, bio-engineering
2.) An organism’s genome is the total DNA in
the nucleus of each cell
GENETIC ENGINEERING
DNA TECHNOLOGY
1.) Biotechnology refers to technology
used to manipulate DNA.
2.) The procedures are often referred to
as genetic engineering.
GENETIC ENGINEERING
DNA TECHNOLOGY
3.) DNA is the genetic material of
all living organisms.
 All organisms use the same
genetic code (A, T, C, G).
RECOMBINANT DNA
- Recombinant DNA refers to the DNA
from the two DIFFERENT organisms.

Can be used for creating transgenic
organisms, gene therapy, and cloning.
RECOMBINANT DNA
-Recombinant DNA
technology was first
used in the 1970’s with
bacteria.
-A plasmid is small ring of
DNA in a bacterium
1st:Remove bacterial DNA
(plasmid).
-Cut the Bacterial DNA
with “restriction enzymes

Restriction enzymes were
discovered in bacteria.
 Bacteria use them as a
defense mechanism to
cut up the DNA of
viruses or other
bacteria

Hundreds of
different restriction
enzymes have been
isolated

Each restriction
enzyme or RE cuts
DNA at a SPECIFIC
base sequence.
MakingRecombinant Bacteria

For example, EcoRI always
cuts DNA at GAATTC as
indicated below
The sequence GAATTC appear three time in the
below strand of DNA, so it is cut into four pieces.
Fragments of DNA that has been cut with
restriction enzymes have unpaired
nucleotides at the ends called sticky ends.
Sticky ends have complimentary bases, so
they could rejoin.
2nd : Cut the gene of
interest from the
organism’s DNA with
same “restriction enzyme”
(RE).
3rd : Combine the “sticky
ends” of the two DNA
pieces together with DNA
ligase (enzyme) – also
known as gene splicing.
 This creates a vector
= a DNA molecule
used to carry a gene
of interest from one
organism to another.

Plasmids & viruses are the most commonly
used vectors
a.) Insert vector into
bacteria.
b.) The bacteria can
now reproduce the
recombinant DNA.
c.) The foreign genes
will be expressed in
the bacteria.
Benefits of Recombinant Bacteria

Bacteria can make
human insulin or
human growth
hormone.
Benefits of Recombinant Bacteria

Bacteria can be engineered to “eat” oil spills.
REVIEW
Plasmids

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Small circular DNA molecules that
can reside in cells.
Often contain genes fro resistance
to antibiotics.
They can spread antibiotic
resistance
They are also used for human
benefit.
Genetic Engineering
Possible because of special
enzymes that cut DNA
 These enzymes are called
RESTRICTION ENZYMES

DNA Scissors: An Introduction
to Restriction Enzymes


Restriction enzymes, are proteins that
recognize and bind to specific DNA
sequences and cut the DNA at or near the
recognition site.
A nuclease is any enzyme that cuts the
phosphodiester bonds of the DNA
backbone, and an endonuclease is an
enzyme that cuts some where within a DNA
molecule.
Restriction enzymes




were originally discovered through their ability to
break down, or restrict, foreign DNA.
can distinguish between the DNA normally
present in the cell and foreign DNA, such as
infecting bacteria virus DNA
The enzymes defend the cell from invasion by
cutting the foreign DNA into pieces, rendering the
DNA nonfunctional.
Restriction enzymes appear to be made
exclusively by prokaryotes.
Restriction enzymes



generally recognize specific DNA
sequences of 4 to 6 base pairs.
These recognition sites are a palindrome
in that the 5’ 3' base sequence is the
same on both strands.
Most of the enzymes make a cut in the
phosphodiester backbone of DNA at a
specific position within the recognition
site, resulting in a break in the DNA.

These recognition cleave
sites are called restriction
sites.
Restriction Enzymes



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Recognize and cut at specific places along
the DNA molecule called restriction sites.
Each different restriction enzyme has its
own type of site.
Restriction site is a 4 or 6 base pair
sequence that is a palindrome.
A DNA palidrome is a sequence in which
the “top strand read from left to right is the
same as the bottom strand read from right
to left.