Define a fermenter.
A fermenter is a controlled environment that has ideal conditions for microorganisms to live in, feed, and produce the proteins needed.
Name 5 things grown through fermenters.
Microorganisms or their products - e.g: Industrial quantities of antibiotics.
Single-cell proteins - e.g: Mycoprotein used in Quorn.
Enzymes for food production - e.g: Chymosin, a vegetarian subsitute for rennin, use in cheese-making.
Enzymes for washing powders - Mainly proteins.
Enzymes to make biofuels - e.g: Ethanol or methane.
Why are bacteria used in genetic and industrial processes?
Simple biochemistry - Easy to work with.
Reproduce very rapidly - Produce the end product quickly and in large amounts.
- Can make complex molecules from simple ones.
Possess DNA as plasmids for ease of modification.
No ethical opposition.
Explain how genetic modification works.
- The desired gene is selected and isolated.
- The desired gene is inserted into the target bacterium using a vector (e.g: A virus or plasmid).
- The gene is replicated.
- The gene is then transferred into the target organism.
- From all the modified individuals, those that show the modified characteristics are selected.
N.B: Stage 5 is achieved by using a marker.
Describe some uses of Genetic Modification.
Any of the following:
- Produce healthier/larger crops with greater yields.
- Produce disease-resistant crops, reducing the need for pollution-causing pesticides.
- Enable some crops (e.g: Bananas) to naturally carry vaccines so they don't need to be kept refrigerated.
- Allow organisations to monitor the release and spread of genetically modified crops by looking for antibiotic-resistant markers in crops.
- Enable some drugs (e.g: Insulin) to be made from human, rather than animal, DNA.
- Make some crops resistant to a herbicide, so that other plants are killed by spraying but not the crop wanted, leading to higher yields and easier harvesting.
What are the disadvantages to genetic modification of plants?
- Plant can cross-pollinate, causing weeds that are resistant to weed killer!
- Could endanger pests or other creatures.
Explain how genetic testing works.
DNA is isolated from the nucleus of a white blood cell. It is usually amplified so that there's enough material to experiment with. It's then broken up into different sized pieces.
- A gene probe is created. This is a single stranded DNA or RNA sequence that has bases which pair up with the complementary bases on the target gene. The probe will only attach if the desired gene is present, so this acts as a marker.
UV is used to locate the marker. If the probe has a marker that causes it to flouresce when UV is shone onto it, the process has been successful.
What is nanotechnology?
The science of working with extremely small structures.
What is biomedical engineering?
Using engineering techniques and ideas to solve medical problems.
Give examples of how nanotechnology can be applied in the food industry.
Biosensors in packaging - Change colour when harmful microorganisms are detected. Extends shelf-life of food.
Nanoparticles in packaging - e.g: Silver nanoparticles to act as a microbial coating to prevent decay and extend shelf-life.
Give examples of how stem cell technology can be applied.
Bone marrow transplants - Stem cells can be used to stimulate the regeneration of white blood cells in the treatment of leukaemia (Blood cancer).
Treating spinal cord injuries - Stem cells can regenerate neurons.
Using cell culture - Stem cells can be grown and transformed into new tissues and organs for transplant.
Give examples of how biomedical engineering can be applied.
Pacemakers - Electrical devices, usually implanted under the skin, to replace the heart's own pacemaker region, the sinoatrial node, to maintain an adequate and regular heartbeat.
Replacement heart valves - Devices that keep the blood flow within the heart efficient if a natural valve malfunctions.
Explain how Stem Cells can be used to treat leukaemia.
Explain the process of DNA Fingerprinting in Genetic Testing.
- DNA is split into 2 sections - Exons (DNA which codes for proteins, usually the same or very similar) and Introns (Also known as minisatellites, DNA that does not code for proteins and is usually unique).
- A good sample is taken, and restriction enzymes are used to cut the DNA into small fragments.
- The minisatellites are heated to 90oC, which splits them apart into 2 strands.
- A complementary strand is added to identify the minisatellite sequences. This is called a DNA probe.
- Then, Gel Electrophoresis is used where the DNA is placed into spaces. An agarose gel is used to conduct electricity, and the DNA will move to the positive end since it is negatively charged. Different parts of DNA will spread out different amounts based on their charge, which creates a fingerprint.
Explain how DNA Profiling is different.
- Small samples are amplified through PCR (Polymerase Chain Reaction).
- A florecent chemical is attached to identify the sequences. This is called a DNA probe.
The problem is that the sample could be contaminated by cells from the person gathering the evidence.
N.B: These are just additional steps.