Biotechnology Flashcards
What is biotechnology and what is it used for ?
Biotechnology is the industrial use of living organisms (or parts of living organisms) to produce food, drugs or other product.
Used for production of food, eg cheese and yogurt
genetically engineered organisms synthesising drugs such as insulin and antibiotics
Why are microorganisms used in processes?
There are no ethical/ welfare issues to consider
Genetic engineering allows us to manipulate organisms to carry out reactions that they normally would not
Short life cycle and rapid growth rate so can produce large manufacturing volumes in a short period of time
Nutrient requirements are simple and relatively cheap
We can genetically modify organisms so that they utilise materials that would otherwise be wasted- raw materials are cheaper
They provide their own catalysts in the form of enzymes and usually require low temperatures/ pressures
What are the disadvantages of using microorganisms ?
Conditions must be sterile- if not this can breed microorganisms that cause the food to go off or causing disease- increase costs
If the conditions are not maintained at the optimum, the microorganisms will not be able to function effectively and may produce toxins
Microorganisms have to be separated from the broth at the end and protein must be purified - increasing costs
Some people may have ethical concerns about eating GM food
Microorganisms mutate quickly so undesirable strains may arise
Examples of microorganisms involved in industrial processes
Baking- yeast
Brewing ethanol- yeast
Cheese making- bacteria
Yoghurt making- bacteria
Penicillin/ Insulin production
What are the advantages of using microorganisms to produce human food ?
Fast reproduction- faster than animals or plants
High protein content with little fat
Can use waste materials- human or animal waste- making the process cheaper
Can be genetically modified to make the protein required
No welfare issues
Can be done at any time- does not depend on eg weather or breeding cycle and can be made to match demand
How is penicillin produced?
A fungus grows, it produces penicillin, drug extracted from medium and purified
Rich nutrient medium, constant supply of oxygen and stirring, buffer to maintain pH
Production of insulin
Previously, pigs were the source of insulin
Hard to isolate, expensive, not as effective as human insulin (some people were allergic due to impurities) , depended on the demand for meat, for some faith groups pig insulin not permitted
Gm insulin less likely to cause an immune response
Bioremediation
Microorganisms are used to break down pollutants or contaminants in the soil or water
1- using natural organisms
2- using GM organisms
Why do health and safety procedures need to be used?
Risk of a mutation taking place making the strain pathogenic
Contamination from pathogenic bacteria within the environment
Aseptic techniques
All work to be carried out in front of a lit bunsen- prevents contamination from the air
Inoculating loop passed through a flame to kill any microorganisms on it
Petri dishes opened as little as possible
Petri dish to be stored upside down to prevent contamination from drops of condensation
Cultures should not be incubated above 25c to restrict the growth of harmful pathogens
Tape the petri dish but not completely shut- allow oxygen in to prevent growth of anaerobic bacteria
Bacteria growth curve
1- Lag : bacteria is adapting to new environment, not yet reproducing at the maximum rate but enzymes needed are being synthesised
2- Log : rate of bacterial production is at/ close to theoretical maximum due to high availability of nutrients and plentiful space
3- Stationary : total growth rate is zero as the number of microorganisms being produced by binary fission = number of microorganisms dying
Limited by resources
4- Decline : death rate exceeds reproduction rate
What are the limiting factors which prevent exponential growth in a colony of bacteria ?
Nutrients available are being used up so eventually it is insufficient to support the growing numbers of bacteria
Oxygen levels decreasing
Carbon dioxide levels increasing- which makes the pH decrease below optimum due to production of carbonic acid- decrease in pH affects enzyme activity, inhibiting population growth
Build up of waste materials can be toxic and inhibit further growth
What is the formula for calculating the number of organisms in a colony?
Final number of bacteria= initial number of bacteria x 2 ^ number of divisions
Why is a logarithmic scale used to represent bacterial populations?
The difference in the numbers of the initial and final population is too large to represent using standard numbers
Allows for a wide range of values to be displayed on a singular graph due to the uneven intervals
How can populations of bacteria be measured?
Direct counting- taking samples to count both living and dead cells
Viable counting- culturing samples of microorganisms and counting the colonies that grow (only living cells are taken into account) - agar
Turbidity- taking an absorbance reading using a colorimeter (takes into account both living and dead cells) - broth
