Biotechnology and Gene Technologies (part2), OCR- unit 5, module 1

Biotechnology and Gene Technologies (part2), OCR- unit 5, module 1

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Sameer Jahabarali Biology
Unit 5 Module 2- Biotechnology and Gene Technologies (part 2)
Genomes and Gene Technologies
A genome of an organism is the entire genetic information found within an organism. Genes found in the
genome code for polypeptides, this is refer to as coding DNA of which only 1.5% of the genome is occupied
these DNA. Whereas the other 98.5% is the non-coding DNA, holding numerous microsatellites (short runs
of repetitive sequences of 3-4 non-coding base pairs that have a regulatory function).
In order to sequence the genome of an organism, the genome must be:
Mapped by locating microsatellites, to identify land marks within DNA sequence to navigate across
the genome or chromosomes
Sheared (mechanically broken) in to smaller sections of 100,000 base pairs (a.k.a. shot gun
approach)
Separated and placed into bacterial artificial chromosome(BACs)
Transferred in to E.coli bacterial cells
The cells grow in culture, so the sections can be copied (cloned) to create a clone library
Each BAC sections are sequenced by:
o Extracting the DNA from the cells
o The DNA is than cut in to smaller fragment of various sizes, using specific restriction enzymes
o The fragments are separated using electrophoresis
o Each fragment is sequence using an automated process (in order of size)
o Computer programmes compare overlapping regions made by different restriction enzymes in
order to reassemble the whole BAC sequence
Gene sequencing allows for genome-wide comparisons between individuals and between species
(comparative gene mapping). Its applications include:
Identification of genes found in all organisms that code for proteins essential for life
Tracking evolutionary relationships (more similar DNA sequence the more closely related species
are)
Modelling effects of change in DNA or genes e.g. yeast with similar genes to humans, can be alters
to see phenotypically changes that may have similar effects on humans.
Comparing genes of pathogenic and non-pathogenic microorganisms to identify which genes cause
disease
Analysis of DNA to reveal mutant alleles

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Sameer Jahabarali Biology
Unit 5 Module 2- Biotechnology and Gene Technologies (part 2)
Electrophoresis is a method of separating DNA fragment in order of their size with the accuracy of one base
length. The technique involves a:
Gel plate containing agarose (sugar), covered in buffer solution.…read more

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Sameer Jahabarali Biology
Unit 5 Module 2- Biotechnology and Gene Technologies (part 2)
Automated DNA sequencer can sequence the DNA in a similar fashion to PCR, where:
The primer anneals to the 3 end base of the template strand
DNA polymerase extends the primer by adding
free nucleotides
However polymerase action is "thrown off"
(stops) when a modified nucleotide (has a
fluorescent marker, and a sugar phosphate
backbone that only react to one adjacent
nucleotide) is added
This generates fragment in sizes that varys of…read more

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Sameer Jahabarali Biology
Unit 5 Module 2- Biotechnology and Gene Technologies (part 2)
Recombinant DNA is a section of DNA formed when by joining DNA sections from two different sources. It is
carried out through:
A DNA Probe (50 to 80 nucleotides long strand) locates the DNA sections required as it anneals
(binds) to the complementary bases in the required gene. It is than detected using: a radioactive
marker (exposed under photographic film) or a fluorescent marker (emits colour under UV light).…read more

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Sameer Jahabarali Biology
Unit 5 Module 2- Biotechnology and Gene Technologies (part 2)
A "heat shock" is given, where temperatures in the culture are lowered to 0oC and quickly raised to
40oC (increases the rate of plasmid intake; however the efficiency is still only 0.25%)
Conjugation, where bacteria's exchange copies genetic material therefore the recombinant plasmid
is also copied among bacteria's even of different species.…read more

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Sameer Jahabarali Biology
Unit 5 Module 2- Biotechnology and Gene Technologies (part 2)
Engineering case studies (insulin and golden rice)
Bacteria can be genetically engineered, using the techniques
studied to produce insulin. This can be done through:
Extracting mRNA that codes for insulin from pancreatic
tissues (islet of Langerhans), using centrifugation
methods to separate mRNA of the right length
The mRNA is used to synthesis the complimentary
DNA strand using reverse transcriptase enzyme.…read more

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Sameer Jahabarali Biology
Unit 5 Module 2- Biotechnology and Gene Technologies (part 2)
Enzymes already present in the endosperm convert carotenoid in to -carotene
Xenotransplantation is the process of transplanting organs or tissues between animals of different species
(allotransplantation- same species). This is done by genetically engineering animals so that they produce
organs or tissues identical to an individual human.…read more

Comments

sara

do you have your notes for reponding to the environment?

angela

hey type in responding to the environment there's a word document available that is really good

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