6.2 Genetic Engineering Flashcards
How has the bacterium E. coli played a role in the development of biotechnology?
Alterations to the genome of E. coli have resulted in a strain that makes high levels of tryptophan, a molecule that can be converted into indigo in a series of steps.
The engineered bacterial strain also contains
a gene from a soil bacterium. The gene is for an enzyme that completes the last step in the conversion of tryptophan to indigo.
Making bio-indigo is less energy intensive than standard methods and does not result in harmful by-products
Describe one use of genetic engineering
We can increase genetic variation in a population by transferring certain genes from one organism to another
List three ways genetic recombination occurs in bacteria
two bacterial cells can form a direct connection.
Viruses can carry bacterial genes from one bacterial cell to another
bacteria can take up loose pieces of DNA from their surroundings
transduction, transformation, conjugation
What is biotechnology? List two
specific examples
The use of organisms to make useful products is called biotechnology.
For example, micro-organisms are used to produce vaccines, antibiotics, hormones, food products(yeast +beer), and enzymes that are added to detergents
Summarize the process of recombinant
DNA technology
they have their own means of genetic recombination.
Scientists have been able to apply these processes to transfer DNA into bacteria + demonstrated that two bacterial cells can form a direct connection.
Using knowledge of the different ways that DNA can be transferred and recombined, people have developed a set of laboratory techniques called recombinant DNA technology.
Recombinant DNA technology combines genes from different sources — even different species — into a single DNA molecule.
How does recombination occur naturally
in bacteria?
Transformation, the uptake of exogenous DNA from the surrounding environment.
Transduction, the virus-mediated transfer of DNA between bacteria.
Conjugation, the transfer of DNA from one bacterium to another via cell-to-cell contact.
What is a recombinant plasmid?
a combination of the original plasmid and
the new DNA`
Why is it useful to have sticky ends on
DNA fragments?
Sticky ends are useful for recombining DNA,
such as plasmid DNA and a human gene.
The complementary sticky ends of two DNA fragments can join together by base-pairing with each other.
What is one way in which genes for antibiotic
resistance spread in a bacterial population?
In some instances, plasmids transfer genes for traits that help bacteria survive, such as genes that make bacteria resistant to antibiotics.
The plasmids carrying these antibiotic-resistance genes can quickly spread throughout a bacterial population.
As a result, an increasing variety of
bacteria that cause human disease are resistant to antibiotics.
What are two uses for recombinant DNA?
Recombinant DNA technology combines genes from different sources — even different species — into a single DNA molecule.
In some cases, it is used to obtain mass quantities of the DNA itself. Gene cloning is the process of putting a recombinant plasmid into a bacterial cell to make copies of a particular gene
What is the difference between cloning a gene
and expressing a gene?
A cloning vector is used to acquire multiple copies of the foreign DNA fragment (gene of interest). An expression vector is utilised to acquire the gene product, which might be RNA or protein, of the DNA (gene of interest)
What are some features of plasmids that make
them useful in genetic engineering?
Plasmids can be used to move pieces of DNA
Contain additional genes that may help the bacteria to adapt to harsher life conditions.
Because of their size, they are easy to pass on to other bacteria of the same species (this is called bacterial conjugation), thus participating in the survival ability of the bacterial strain
Is genetic engineering the same as
biotechnology? Explain
Genetic engineering is the modification of genome of an organism to yield a desired outcome, whereas biotechnology is the use of a biological system, product, derivative, or organism in a technological aspect to benefit financially. Genetic engineering is an application of biotechnology
How is bio-indigo produced?
Alterations to the genome of E. coli have resulted in a strain that makes high levels of tryptophan, a molecule that can be converted into indigo in a series of steps.
The engineered bacterial strain also contains
a gene from a soil bacterium. The gene is for an enzyme that completes the last step in the conversion of tryptophan to indigo.
What are the advantages of bio-indigo
over other sources of indigo?
Making bio-indigo is less energy intensive than standard methods and does not result in harmful by-products.
What could you use as an indicator that
bacterial cells have picked up recombinant
plasmids?
?
Cells containing recombinant plasmids can often be identified as containing recombinant plasmids by screening for the insertional inactivation of a second genetic marker on the plasmid.
appearance of sticky ends?
How could you use bacteria to make copies
of a gene?
Gene cloning: process of putting a recombinant plasmid into a bacterial cell to make copies of a particular gene.
How is selective breeding similar to genetic
engineering?
Selective breeding and genetic engineering are two methods used to produce new organisms with desired characteristics.
Both are artificial methods that occur under the influence of humans
example of genetic engineering
blue jeans going green(environmently friendly)
-Change in the fabric dying process
-Traditionally indigo (blue) dye was derived from plants
-Synthetic production involving coal or oil became the new standard, although produces toxic by-products, so…
-NEW environmentally friendly substitute is bio-
indigo from bacteria
Alterations to the genome of E. coli have resulted in a strain that makes high levels of
tryptophan
tryptophan
a molecule that can be converted into indigo through a series of steps
Bio-indigo uses _____ to make and does not result in harmful _____
less energy; by-products
biotechnology
The use of organisms to make useful products
E.g. vaccines, antibiotics, and hormones
genetic engineering
-Genetic Engineering
-The intentional production of new genes and alteration of genomes by the substitution or introduction of new genetic material
-We can tailor the abilities of living organisms to meet needs in agriculture
-Referred to as Genetically Modified Organisms (GMOs)
what is it called when we can tailor the abilities of living organisms to meet needs in agriculture
genetically modified organisms (GMOs)
examples of GMOs
Vegetable oil (from GM crops: canola, soybeans, corn; resistant to herbicides, improved oil composition)
BT-Corn (produces own pesticides against insects)
Salmon (grow to market size in half the usual time)
Rice (increased iron & other vitamins)
Bt corn
produces own pesticides against insects
Possibilities of GMOs
Future possibilities:
Bananas with human vaccines against hepatitis B
Cows with bovine spongiform encephalitis (Mad Cow Disease) resistance
Plants that produce plastics
_______ are essential to modern biotech.
by engineering bacteria, we can use them to mass produce ________________
Bacteria; useful genes and proteins
Knowing this info. about bacteria Recombinant DNA Technology allows scientists to
combine genes from different sources – even different species – into a single DNA molecule.
making recombinant DNA
Bacteria contain plasmids
-separate from the much larger bacterial chromosome
Plasmids may contain a number of genes and can make copies of themselves
-bacteria can share genes via conjugation, and then pass them on to the next generation via binary fission
Bacteria contain
plasmids
Plasmids may contain a number of genes and can make copies of
themselves
Bacteria can share genes via ______, and then pass them on to the next generation via binary fission
conjugation; binary fission
Bacteria can pass down ___________ to other bacteria (e.g. __________)
useful traits; antibiotic resistance
why is antibiotic resistance bad?
-individual bacteria can undergo random mutations →some mutations can make bacteria resistant to a certain antibiotic
-Can quickly spread throughout a bacterial population
-Therefore, an increase in antibiotic-resistant bacteria
Plasmids can also be used for
human benefit
how can plasmids be used for human benefit?
Plasmids can also be used for human benefit
E.g. moving pieces of DNA, such as the gene for producing indigo dye, into bacteria
making recombinant DNA
-Plasmid is removed from bacterial cell
-Desired gene is inserted into the plasmid
-Result is recombinant plasmid (combo of original plasmid and the new DNA)
-Recombinant plasmid put back into bacterial cell, where the DNA can replicate many times as the cell reproduces
recombinant plasmid
combo of original plasmid and the new DNA
cutting and pasting DNA
Requires 2 main steps
-“cutting and pasting”
DNA containing the gene must be “cut” out of a longer DNA molecule
-restriction enzymes are used for cutting the DNA
-make staggered cuts with “sticky ends”
-available to bind to any sequence that is complimentary to it
-complimentary sticky ends of 2 DNA fragments can join together by base-pairing with each other
DNA ligase “pastes” the sticky ends back together
Restriction enzymes are used for ___________
cutting the DNA
DNA ligase
“pastes” the sticky ends back together
Complimentary sticky ends of 2 DNA fragments can join together by _______ with each other
base-pairing
what is CRISPR
CRISPR can make fast, large scale changes to entire species, changing their genetic makeup
function of CRISPR and give an example
instead of targeting isolated groups of insects → they change the types that transmit diseases
using genetic engineering
-scientists have successfully created a strain of mosquitoes that are immune to malaria parasite by adding a new antibody gene that specifically targets plasmodium (these mosquitoes will never spread malaria)
-changing just the genetic information is not enough (unchanged mosquito can pass trait to offspring)
a genetic engineering method called the gene drive solves this problem→forces new gene to become dominant in following generations
release engineered mosquitoes into wild → malaria blocking gene would spread quickly and malaria could disappear
cons of CRISPR
-could be consequences for editing nature (worst case scenario in malaria case→doesn’t work or parasite adapts in negative way)
-unethical to not use CRISPR → diseases kills millions of people each day
