Lesson 4: Biotechnology Flashcards
Why is biotechnology often shown as being controversial in media reports?
because biotechnology has implications for many different considerations in society, such as legal, ethical, economic, political, and environmental factors, these considerations can sometimes be contradictory. For example, a new biotechnology may have a medical benefit, but its production could harm the environment, so its difficult for society to decide whether it is a good or bad invention overall.
What is the main benefit of DNA barcoding?
Its the tool used to find out the species names, so that you can get information about the species
How does DNA barcoding work?
A short segment DNA taken from a standardized location in the genome, is sequenced from a specimen. This sequence is compared to a database of known sequences to identify to which species the specimen belongs
List 2 benefits and 2 potential drawbacks of DNA barcoding
benefits:
- fast
- accurate
drawbacks:
-It doesn’t yet work for all types of species especially plants
List 3 key developments in this history of biotechnology that directly relate to the DNA barcoding project
- Discovery of the structure of DNA
- Electrophoresis
- PCR
What are the 5 techniques when working with DNA
- Extraction
- Electrophoresis
- Amplication (PCR)
- Sequencing
- Recombinant DNA
How did the discovery of restriction enzymes allow biologists to work with DNA samples?
Restriction enzymes allow biologists to cut DNA at known locations into short sequences. The DNA fragments can then be analyzed, removed, or inserted into the DNA of other individuals. RE makes genetic engineering possible.
What roles do the electrical current and the agarose gel play in sorting DNA samples according to their different sizes
because DNA is negatively charged, it will move towards the positive end of the gel when an electric current is applied to the gel. The electric current provides the pull that drags the DNA fragments through the gel. Agarose gel is like an obstacle course that slows the larger DNA molecules down, as they pass through it. The smaller fragments will move faster than the larger ones, so they will the positive end of the gel fastest.
Describe the unique feature of Taq poly,ease that makes PCR possible
its optimal acitivity occurs at a high temperature (72 celcius). Most emzymes denature above 40 celcius. Therefore, the DNA sample being amplified can be seperated cleanly by raising the temp, while the activity of the enzyme is improved. This speeds up the replication process greatly.
Explain why PCR needs to be carried out at three different temperatures.
PCR requires 3 steps and each one occurs at a different optimal temperature. The first step is to denature, or split apart the DNA molecule. At 94 celcius, this will happen naturally, without the use of enzymes. the next step is attachment of the primer molecule to the exposed DNA templates. This is called annealing and happens most effectively at around 60 celcius. The final step is the addition of new nucleotides to the growing DNA strand. This elongation step occurs with the help of Taq polymerase, whcih is optimally active at 72 degrees.
What are ddNTPs and how are they used to sequence DNA?
they are artificially formed chemical versions of regular DNA nucleotides, excpet that they do not have the 3 prime -OH bonding site, which means that no other nucleotide can bond to them after they have joined an elongating strand of DNA. This causes the DNA replication to stop, after they have been added.
Why are the ddNTPs labelled with fluorescent molecules?
so that they will glow with a particular colour, when exposed to strong light, such as a laser. This way all the four different ddNTPs have a different color and can be uniquely distinguished by a camera and software system. This allows the DNA sequence to be recorded as the ddNTPs flow through the capillary tube, past the laser.
What is recombinant DNA?
its the result of removing genetic material from one genome and inserting it into another genome. This is often done across species to create transgenic organisms.
What is one useful product produced by recombinant DNA?
Insulin is a hormone needed by millions of diabetics around the world. Producing insulin in transgenic bacteria creates a cheap, plentiful supply that does not cause the same allergy problems as the old source of insulin obtained from animals.
What is the role of restriction enzymes in the process of making recombinant DNA?
Restriction enzymes are designed to cut the DNA at particular locations. They are like molecular scissors that can be designed to cut out specific genes or fragments of genes
