Biology π | Biotechnology | 21 Flashcards
List the reasons why bacteria are useful in biotechnology.
- Rapid reproduction rate
- Ability to make complex molecules
- There are no ethical concerns over their manipulation and growth
- They posess plasmids
Why are plasmids useful in genetic modification?
The presence of plasmids in bacteria, separate from the main bacterial chromosome, makes them easy to remove and manipulate to insert genes into them and then place back inside the bacterial cells.
List the examples we have studies showing uses of biotechnology.
- Producing ethanol for biofuels
- Bread-making
- Fruit juice production
- Biological washing powders
- Creating lactose-free milk
- In a fermenter:
- Insulin
- Penicillin
- Mycoprotein
What is yeast?
A single celled fungus that uses sugar as its food source
How does yeast create energy?
Anaerobic respiration
What are the products of anaerobic respiration in yeast?
Ethanol + Carbon dioxide + Energy release
What is the ethanol from anaerobic respiration in yeast often used for?
biofuels
Define biofuel
A fuel made from living organisms rather than a fossil fuel such as oil coal or gas
Why is plant material needed in the production of biofuels?
It is used as the substrate for producing ethanol, as a source of glucose
What kinds of plants are used to produce biofuels?
- Waste parts of crop plants such as stalks or outer leaves
- Crops grown specifically to be harvested for making ethanol
What is the role of anaerobic respiration in bread-making?
Yeast respires anaerobically with access to the sugar of the dough, and the carbon dioxide produced in anaerobic respiration causes the bread to rise
Which product of anaerobic respiration is used in bread-making?
Carbon dioxide
What is the downside of traditional fruit juice production, without pectinase?
All the cells are not broken open so a lot of juice is lost
What enzyme is used in fruit juice production?
Pectinase
Why do we use pectinase in fruit juice production?
- To release more juice
- To make the juice clearer
How does pectinase help in fruit juice production?
- Pectinase breaks down a chemical in plant cell walls
- Cell walls break more easily and more juice is squeezed out of the fruit
What chemical does pectinase break down?
Pectin, found in plant cell walls
How does juice become clearer after the use of pectinase?
Polysaccharides like pectin can make the juice seem cloudy.
What sort of enzymes are found in biological washing powders?
Similar enzymes to those produced in the alimentary canal
What are the advantages of biological washing powders?
- Quickly breaking down large, insoluble molecules such as fats and proteins
into smaller, soluble ones that will dissolve in washing water - Effective at lower temperatures, meaning less energy (and money) has to be used in order to wash clothes to get them clean as washing water
- Can be used to clean delicate fabrics that would not be suitable forwashing at high temperatures
Why do we make lactose free milk?
In some areas of the world people become lactose intolerant as they age, losing the enzyme they are born with that breaks down lactose in milk. This causes issues in the digestive system.
What enzyme breaks down lactose?
Lactase
How can milk be made lactose free?
By adding the enzyme lactase to it and leaving it to stand for a while to allow the enzyme to break down the lactose
What is penicillum?
A mould that produces a penicillin
What is penicillin?
An antibiotic that interferes with the building of bacterial cell walls
Where is insulin, penicillin, and mycoprotein produced on a large scale?
An industrial fermenter
What is a fermenter?
Containers used to grow (βcultureβ) microorganisms like bacteria and fungi in large amounts
What is the advantage of culturing microorganisms in a fermenter?
Conditions can be carefully controlled to produce large quantities of exactly the right type of microorganism
List the conditions that need to be controlled in a fermenter.
- Aseptic precautions
- Nutrient supply
- Temperature
- pH
- Oxygenation
- Agitation
Why and how are aseptic precautions controlled in a fermenter?
Fermenter is cleaned by stem to kill microbes and prevent chemical contamination which ensures only the desired microbes will grow
Why and how are nutrients controlled in a fermenter?
Nutrients are needed for use in respiration to release energy for growth and to ensure that the microbes are able to reproduce
Why and how is temperature controlled in a fermenter?
Temperature is monitored using probes and maintained using the water jacket to ensure an optimum environment for enzymes to increase enzyme activity
Why and how is pH level controlled in a fermenter?
pH inside a fermenter is monitored using a probe to check it is at the optimum value for the particular microbe being grown. The pH can be adjusted if necessary, using acids or alkalis
Why and how is oxygen level controlled in a fermenter?
Oxygen is supplied through a steam pipe and removes through an exhaust outlet because it is needed for aerobic respiration to take place
Why and how is agitation controlled in a fermenter?
Stirring paddles ensure that microbes, nutrients, temperature, and pH is evenly distributed in the fermenter
How does a fermenter work
(imaaagine the diagram \~~)
Define genetic modification
Changing the genetic material of an organism by removing, changing or inserting individual genes
What is the βtransgenic organismβ?
The organism recieving the genetic material that is genetically modified
What is the βrecombinant DNAβ?
The DNA of the organism that now contains DNA from another organism as well
List the examples of genetic modification.
- The insertion of human genes into bacteria to produce human proteins
- The insertion of genes into crop plants to confer resistance to herbicides
- The insertion of genes into crop plants to confer resistance to insect pests
- The insertion of genes into crop plants to improve nutritional qualities
What sort of genes may be added to crop plants?
- Genes from bacteria producing poison that kills insects
- Genes that make them resistant to certain herbicides
- Genes from other plants that make them produce more of a certain vitamin
What sort of genes may be added to crop plants?
- Genes from bacteria producing poison that kills insects
- Genes that make them resistant to certain herbicides
- Genes from other plants that make them produce more of a certain vitamin
What are the advantages of GM crops?
- Less use of chemicals such as herbicides and pesticides is better for the environment and cheaper and less time consuming
- Increased yield from crops as they donβt compete with as many weeds
List the disadvantages of GM crops?
- Increased seed costs
- Increased dependency on certain chemicals
- Risk of inserted geners being transferred to wiild plants by pollination making GM crops less useful
- Reduced biodiversity
How do GM crops have increased seed costs?
Companies that make GM seeds charge more for them to cover the cost of developing them
How do GM crops lead to increased dependency on chemicals?
Use of herbicides that the crops are resistant to increases
How do GM crops reduce biodiversity?
Fewer plant species when herbicides are used
Quickly outline the process of genetic modification.
- Isolation of the DNA making up a human gene
- Cutting of bacterial plasmid DNA
- Insertation of human DNA into bacterial plasmid DNA
- Insertation of recombinant plasmids into bacteria
- Multiplication of bacteria with recombinant plasmids
- Expression in becteria of the human gene to make the human protein
How is the DNA from the human gene isolated?
Restriction enzymes isolate the gene, leaving it with βsticky endsβ
Define sticky ends
A short section of unpaired bases
How is the DNA of a bacterial plasmid cut?
It is cut using the same restriction enzyme leaving it with corresponding sticky ends
Why are both the human and bacterial DNA cut using the same restriction enzyme?
This leaves them with complementary sticky ends, allowing them to join together after action of DNA ligase
What is the role of DNA ligase?
It joins together the cut plasmid and the isolated genne
What do you call a genetically modified plasmid?
Recombinant plasmid
What is done after a plasmid is genetically modified?
It is inserted into a bacteria, which is placed into a fermenter to reproduce quickly.
