Biotechnology and genetic modification Flashcards
Why are bacteria useful in biotechnology and genetic modification?
- Their rapid reproduction rate
- Ability to make complex molecules
- Few ethical concerns over their manipulation and growth
- The presence of plasmids (plasmids are small, circular loops of DNA which can be an ideal way of transferring DNA from one cell to another during genetic manipulation)
The role of anaerobic respiration in yeast during the production of ethanol for biofuels
The anaerobic respiration in yeast is what breaks down the glucose into ethanol and carbon dioxide. The ethanol can be used to make biofuel
The role of anaerobic respiration in yeast during bread-making
The anaerobic respiration in yeast is what breaks down the glucose into ethanol and carbon dioxide. The carbon dioxide produced during fermentation causes the dough to expand, creating small air pockets that make the bread rise and give it a light, fluffy texture.
Use of pectinase in fruit juice production
Pectinase is an enzyme which is added to the chopped up fruit to break down the pectin in the cell walls. It makes fruit juice clear by breaking down pectin which makes fruit juices cloudy and thick. Additionally, by breaking down the fruit’s cell walls, pectinase helps release more juice from the fruit, increasing the total yield.
The use of biological
washing powders that contain enzymes
Stains are often made of organic molecules like proteins and fats which is why digestive enzymes can be used to clean them. They are broken down into smaller water soluble molecules making them easier to wash out. They work best at lower temperatures and neutral pH.
How is lactase used to produce lactose free milk?
When lactase is added to milk after leaving it for a while it breaks down the lactose into molecules that are fine for the gut
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 are fermenters used for?
Fermenters are large vessels used to grow microorganisms, such as bacteria and fungi, under controlled conditions to produce useful products on an industrial scale. These products include insulin, penicillin, and mycoprotein.
How is insulin grown in a fermenter?
Insulin (by bacteria):
Genetically engineered bacteria, often E. coli, are used to produce human insulin.
The gene for human insulin is inserted into bacterial DNA, allowing the bacteria to synthesize insulin, which is then harvested, purified, and used for medical purposes in the treatment of diabetes.
How is penicillin grown in a fermenter?
Penicillin (by fungi):
The fungus Penicillium is grown in fermenters to produce penicillin, a widely used antibiotic.
Penicillin is secreted by the fungus during growth and is extracted from the fermenter for purification and use in medicine.
How is mycoprotein grown in a fermenter?
Mycoprotein (by fungi):
Fusarium fungus is used to produce mycoprotein, a protein-rich food product used as a meat substitute.
The fungus grows in large fermenters, where the mycoprotein is harvested, processed, and used in products like Quorn.
Conditions that need to be controlled in a fermenter
Temperature
Why it needs to be controlled: Enzymes within microorganisms work best at an optimum temperature. Too high a temperature can denature enzymes, stopping growth, while too low a temperature slows down metabolic processes.
How it is controlled: Cooling jackets or heaters are used to maintain the ideal temperature for the microorganisms.
pH
Why it needs to be controlled: Microorganisms have an optimum pH range at which their enzymes function efficiently. If the pH becomes too acidic or too alkaline, enzyme activity is affected, and growth may stop.
How it is controlled: pH sensors monitor the acidity or alkalinity of the fermentation broth, and acids or bases are added to maintain the correct pH.
Oxygen Supply
Why it needs to be controlled: Many microorganisms, including those used in the production of insulin and mycoprotein, require oxygen for aerobic respiration. Insufficient oxygen can slow down growth and reduce product yield.
How it is controlled: Air is pumped into the fermenter, and stirrers or paddles ensure that oxygen is evenly distributed throughout the culture.
Nutrient Supply
Why it needs to be controlled: Microorganisms need nutrients (such as glucose, nitrogen, and minerals) for growth and product synthesis. A continuous supply ensures that the microorganisms remain active and productive.
How it is controlled: Nutrients are continuously added to the fermenter to keep the microorganisms in the growth phase and to maximize product yield.
Waste Product Removal
Why it needs to be controlled: As microorganisms grow and metabolize, they produce waste products (such as carbon dioxide, acids, or alcohols) that can build up and inhibit growth if not removed.
How it is controlled: Fermenters are equipped with systems to remove or neutralize waste products to prevent toxicity or adverse effects on the microorganisms.
Genetic modification definition
genetic modification is changing the genetic material of an organism by removing, changing or inserting individual genes
Process of genetic modification using
bacterial production of a human protein
- isolation of the DNA making up a human gene using restriction enzymes, forming sticky ends
- cutting of bacterial plasmid DNA with the same restriction enzymes, forming complementary sticky ends
- insertion of human DNA into bacterial plasmid DNA using DNA ligase to form a recombinant plasmid
- insertion of recombinant plasmids into bacteria
- multiplication of bacteria containing
recombinant plasmids - expression in bacteria of the human gene to make the human protein
Advantages of genetically modifying crops
- Reduced use of chemicals such as herbicides and pesticides (better for the environment)
- Increased yields from the crops as they aren’t competing with the weeds
