21 Biotechnology and genetic modification Flashcards
why is bacteria useful in biotechnology and genetic modification
- rapid reproduction
- ability to make complex molecules
- few ethical concerns over their manipulation and growth
- the prescence of plasmids
how are some biofuels made
the ethanol produced by yeast during fermentation can be used as a bio fuel
how is fermentation required for bread making
the carbon dioxide produced by yeast when making bread causes bread to rise as it creates air bubbles
how to produce fruit juice
add pectinase to chopped of fruit to release more juice when squeezed
- pectinase breaks down pectin that is a chemical found in plant walls
- once pectin is broken, the cell walls break down more easily and more juice can be squeezed out
- also makes juice clearer as pollysaccharides that make it cloudy are broken down into smaller molecules
describe the use of biological washing powders that contain enzymes
most stains consist of organic molecules (fat, protein, lipids). detergents contain enzymes to break down large food molecules
- quickly digests food to be soluble in washing water
- effective at lower temps, less energy and money needs to be used
- can clean delicate fabrics that would not be suitable for high temps
how to produce lactose free milk
add the enzyme lactase to milk to break down the lactose into 2 simple sugars (galactose and glucose)
what is lactose intolerant?
lactose is a sugar. people who are lactose intolerant cannot produce lactase to digest lactose. resulting in nausea, flatulence and diarrhoea.
how can fermenters be used for large scale production of useful products
involves the growth of microorganisms in a controlled environment to produce desired products
useful products made by fermenters
bacteria, fungi, insulin, penicillin and mycoprotein
Fermenter condition: Nutrients (how and why is it controlled)
Microorganisms require an energy source - usually carbohydrates. They also require growth materials such as amino acids for protein synthesis
Fermenter condition: Temperature probe & acidity probe (how and why is it controlled)
Correct any changes to maintain the optimum conditions for fermentation
Fermenter condition: Water jacket (how and why is it controlled)
To control temperature to ensure that it is high enough to promote enzyme activity but not too high that enzymes and other proteins in the microbes are denatured
Fermenter condition: Gas outlet (how and why is it controlled)
Gas may be evolved during fermentation. This must be released to avoid pressure build up. It may be a valuable by product e.g. CO2 can be collected and sold for use in fizzy drinks
Fermenter condition: Stirrers (how and why is it controlled)
These continuously mix the contents of the bioreactor to:
1. Ensure the microbes are always in contact with nutrients
2. Ensures an even temperature throughout
In aerobic mixing may be carried out by an air stream
Fermenter condition: Acid/alkai inlet (how and why is it controlled)
Correct any changes to maintain the optimum pH conditions for fermentation
Fermenter condition: sterile air/steam inlet (how and why)
Provide oxygen as well as the culture must be sterile to:
To avoid competition for expensive nutrients
Limit the danger of disease causing organisms contaminating the product
genetic modification
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
- multiplicaiton of bacteria containing recombinant plasmids
- expression in bacteria of the human gene to make the human protein
why insert genes into crop plants?
- to confer resistance to herbicides
- to confer resistance to insect pests
- to improve nutritional qualities
advantages of genetically modifying crops
- reduced use of chemicals - heribicides and pesticides - which is better for the environment and less time-consuming for farmers
- increased yields from the crops as they are not competing with weeds for resources or suffering from pest damage
disadvantages of genetically modifying crops
- increased cost of seeds
- increased dependency on certain chemicals
- risk of inserted genes being transferred to wild plants by pollination which could reduce the usefulness of the GM crop
- reduced biodiversity as existing species can be overrun by more dominant new species
- research suggests GM plants do not grow as well as non GM plants
