Plasmids | Genetics | Biology
Summary
TLDRThis script discusses the role of plasmids in genetic engineering, highlighting their utility in transferring antibiotic resistance genes between bacteria. It explains the process of using restriction enzymes to cut and insert desired genes into plasmids, which are then introduced into bacteria. The script also touches on techniques for inserting genes into the chromosomes of complex organisms, such as plants and animals, through vector methods, which involve using organisms to carry and insert DNA.
Takeaways
- 🧬 Bacteria provide genetic engineers with tools like restriction enzymes and plasmids for genetic manipulation.
- 🔄 Plasmids are small, circular DNA molecules that can replicate independently within bacteria, offering a means for horizontal gene transfer.
- 🌐 Plasmids can carry genes for traits not present in the bacterial chromosome, such as antibiotic resistance.
- 🚀 When a bacterium dies, it releases plasmids that can be taken up by other bacteria, thereby spreading new traits.
- 🧪 Genetic engineers use restriction enzymes to cut plasmids and insert desired genes, then use repair enzymes to recombine the DNA.
- 🌡️ A specific technique involves growing bacteria with the new plasmids in a culture and using antibiotics to select for bacteria that have successfully incorporated the plasmids.
- 💊 The engineered bacteria can be used to produce therapeutic proteins like insulin or growth hormones, which can then be extracted and purified for medical use.
- 🌱 For more complex organisms, two major methods are used to insert DNA into cells: vector and non-vector methods.
- 🔬 Vector methods use organisms to carry and insert DNA from one species into another, bypassing the need for a third organism.
- 🎵 The script is accompanied by music, suggesting it is part of a multimedia presentation aimed at educating about genetic engineering.
Q & A
What is the role of bacteria in genetic engineering?
-Bacteria play a crucial role in genetic engineering by providing genetic engineers with restriction enzymes and plasmids, which are essential tools for DNA manipulation and recombination.
What are plasmids and how are they different from bacterial chromosomes?
-Plasmids are small, circular DNA molecules that are separate from the bacterial chromosome. They are typically 1,000 to 100,000 nucleotides long and can replicate independently within bacteria.
How do plasmids contribute to DNA recombination in nature?
-Plasmids contribute to DNA recombination by allowing the transfer of genetic traits not found in the bacterial chromosome to other bacteria. This can include resistance to antibiotics or the ability to produce certain enzymes.
Why are plasmids advantageous to bacteria?
-Plasmids can provide bacteria with advantageous traits such as antibiotic resistance, which helps them survive in environments where antibiotics are present.
How do genetic engineers manipulate plasmids to insert desired genes?
-Genetic engineers use restriction enzymes to cut plasmids, then add repair enzymes to join the desired gene segment with the plasmid, creating a new plasmid with the inserted gene.
What is the process of introducing new plasmids into bacteria?
-New plasmids are introduced into bacteria by placing them in a solution that allows the plasmids to penetrate the bacterial cell wall and membrane, after which the bacteria are cultured to allow the plasmids to be taken up.
How do genetic engineers select for bacteria that have taken up the new plasmids?
-Engineers use a selection process involving antibiotics. Bacteria that have not taken up the new plasmids are killed off by the antibiotics, while those that have and possess antibiotic resistance genes continue to grow.
What is the purpose of growing bacteria in culture after plasmid insertion?
-Bacteria are grown in culture to allow for the production of sufficient quantities of the desired product, such as insulin or growth hormones, which can then be extracted and purified for use.
What are the two major methods for inserting DNA into the nuclei of eukaryotic cells?
-The two major methods for inserting DNA into the nuclei of eukaryotic cells are vector methods and non-vector methods. Vector methods involve the use of an intermediate organism to deliver the DNA.
What is a vector in the context of genetic engineering?
-In genetic engineering, a vector is an organism or molecule that carries and delivers DNA from one species into another, facilitating the transfer and insertion of genetic material.
Outlines
🔬 Bacteria and Genetic Engineering
Bacteria have been instrumental in genetic engineering, especially through the use of plasmids. In addition to their primary chromosome, bacteria carry small rings of DNA called plasmids, which range from 1,000 to 100,000 nucleotides in length. These plasmids serve as independent, self-replicating DNA molecules that can be transferred between bacteria, enabling them to gain traits such as antibiotic resistance. This natural process is key in genetic recombination.
🧬 Genetic Engineering with Plasmids
Genetic engineers use plasmids in their experiments by cutting them with restriction enzymes and inserting desired gene segments. Repair enzymes are used to rejoin the DNA fragments. These engineered plasmids, now containing new genetic material, are introduced into bacteria through a solution that makes the bacteria absorb the plasmids. Afterward, the bacteria are cultured for a brief period to grow and multiply.
💉 Selecting Bacteria with Desired Genes
To ensure that the bacteria absorb the new plasmids, scientists expose the cultured bacteria to antibiotics like ampicillin and amoxicillin. Only the bacteria that have successfully absorbed the plasmids with antibiotic resistance survive, while others die off. These surviving bacteria, now carrying genes such as those for insulin or growth hormone production, are then cultivated further.
🧪 Large-Scale Production of Hormones
Scientists continue to grow the bacteria that absorbed the plasmids until they produce sufficient quantities of desired proteins, such as insulin or growth hormones. These proteins are then extracted and purified for medical use in human patients.
🌱 Genetic Engineering in Complex Organisms
Inserting genes into more complex organisms, such as plants or animals, requires different methods. There are two primary approaches: vector and non-vector methods. Vector methods involve using organisms that carry and insert DNA from one species into another, whereas non-vector methods do not require an intermediate organism for DNA delivery.
Mindmap
Keywords
💡Plasmids
💡Restriction enzymes
💡Self-replicating
💡Antibiotic resistance
💡DNA recombination
💡Culture
💡Vector methods
💡Eukaryotic cells
💡Insulin
💡Repair enzymes
Highlights
Bacteria provide genetic engineers with restriction enzymes and plasmids.
Plasmids are tiny, self-replicating DNA rings within bacteria.
Plasmids facilitate DNA recombination in nature.
Some plasmids carry genes for antibiotic resistance.
Plasmids can be released and taken up by other bacteria, transferring traits.
Genetic engineers use restriction enzymes to cut plasmids for gene insertion.
Repair enzymes join DNA pieces together at their sticky ends.
New plasmids with inserted genes are introduced into bacteria.
Bacteria with new plasmids can be selected using antibiotic resistance.
Genetic engineering can produce insulin or growth hormones in bacteria.
There are two major methods for inserting DNA into eukaryotic cells: vector and non-vector methods.
Vectors are organisms that carry and insert DNA from one species into another.
Vector methods do not require an intermediate organism for DNA delivery.
The process of inserting genes into chromosomes of complex organisms is discussed.
Genetic engineering techniques have practical applications in medicine.
Bacteria can be grown to produce sufficient quantities of therapeutic proteins.
The transcript discusses the innovative methods of genetic engineering.
The significance of plasmids in genetic engineering and their role in antibiotic resistance is highlighted.
Transcripts
[Music]
bacteria have been helpful to genetic
Engineers not only in providing them
with restriction enzymes but also with
what are called
plasmids in addition to their single
chromosome many bacteria also contain
tiny rings of DNA called plasmids
plasmids are usually about 1,000 to
100,000 nucleotides long and act as
independent self-replicating molecular
operators within
bacteria plasmids are one of the ways
that DNA recombination goes on within
nature while a bacteria's chromosome
contains all the necessary genes to code
for the bacteria's Existence plasmids
provide an effective way by which traits
not contained in the chromosome can be
passed from bacteria to
bacteria for example some plasmids
contain genes that code for enzymes that
digest certain antibiotics such as
penicillin or ampicillin this is
obviously an advantage to the bacteria
when a bacteria containing these
plasmids dies it breaks open and
liberates these plasmids to the outside
environment and they are often taken up
by other bacteria that then acquire the
traits coded for by the
plasmids genetic Engineers can place
liberated plasmids in a solution with
restriction enzymes and cut them apart
the engineers then place the gene
segment they wish to insert into the
solution with the plasmids and then add
repair enzymes that join the pieces of
DNA together at their sticky ends these
new plasmids with their newly inserted
genes are then placed with bacteria into
a different solution that enables the
plasmids to readily penetrate through
the cell wall and membrane of bacteria
the bacteria that are exposed to the
plasmids are taken out and grown in a
culture for a short
time if the plasmids into which the
experimental Gene such as the gene for
the production of insulin a growth
hormone is inserted also have genes that
provide resistance to ampicillin and
Amoxicillin a unique technique can be
used genetic Engineers know that not all
the bacteria exposed to the plasmids
will absorb them by exposing the
cultured bacteria to antibiotics such as
ayin and Amoxicillin they kill off the
bacteria that didn't absorb the new
plasmids well those bacteria that did
absorb the new plasmids containing the
genes for antibiotic resistance and for
say insulin or growth hormone continue
to grow and thrive in the
culture scientists continue to grow
these bacteria until the insulin or
growth hormone produced by them is
sufficient to be extracted and purified
for use by human
patients but how are genes inserted into
the chromosomes and DNA of more complex
organisms such as plants or animals
there are two major methods of placing
DNA into the nuclei of eukaryotic cells
vector and Vector methods Vector methods
of insertion of DNA don't require the
use of a third intermediate organism to
deliver the DNA from one species to
another vectors in the B biological
sense of the word are organisms that
carry the DNA of one species and insert
it into another
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