Module 6: Cloning And Biotechnology Flashcards
What is a clone
a genetically identical organism or cell
What is natrual plant cloning known from non reproudcive tissues known as
vegatative propogation
What are the different types of ways that plants can natrually clone themselves
Rhizomes: stem structures that grow horizontally underground, away from parent plant. These have nodes where new shoots can develop
Stolons: also known as runners, grow above ground. These have nodes where new shoots can develop (examples inculde strawberries)
Suckers: shoots that grow from sucker buds, present in roots of parent plant. An example of this is a elm tree
Tubers: large underground plant structures that act as food store, covered in eyes and each eye can sprout to form a new plant (example is potatoes)
Bulbs: underground food stores, new bulbs can develop from orginal bulbs to form individual plants
How can vegetative propgation be used in horticulture or agriculture
- Can take cuttings
- Use grafting: when you join shoot from one plant to the growing stem of another plant
- Layering: when you bend a stem downwards, so it enters the soil and grows a new plant
Why do plants do vegetative propogation
- only need one parent so its faster
- all are genetically identical, no genetic variation so if conditions are favourable then its good, as they can survive and reporduce
- downside is if conditions change then they may die
How can we produce clones from cuttings
- use a scalpel from stem at 45 degrees
- remove leaves leaving just one at the tip
- Dip lower end of cutting in rooting powder
- Place cutting in plant with suitible growth meidum
- Place pot in a warm and suitlbe condition (moist soil, humid air which reduces transpiration stress), can cover pot with plastic bag to achieve this
- When cutting forms its own roots can plant elsewhere so it can grow
Where else can you take cuttings of a plant apart from the stem
- Root cutting, use kind of the same method, dip in rooting powder and place in suitble growth medium
- Leaf-cutting (split vein cutting): when you remove a complete leaf and large veins on lower leaf using a scalpel, then place on growth medium, with broken veins facing down
How is tissue culture carried out
- Cells from orginal plant taken from root and stem (where the meristem is)
- Cells steralised using bleach ethanol to kill any micro-organisims (bacteria and fungi will compete from nutrients decreasing growth rate)
- Explant placed in medium containing amino acids, glucose and high conc of plant horomones . Carried out in aspectic conditions, and cells proudce mass of cells called a callus
- Callus is divided up and placed in new medium contaiing nutrients and hormones, this stimulates development of plantlets
- Young planlets are taken out to grow
What is micro-propogation
- when tissue culture is used to produce many plants quickly
- cells are taken and subcultured and this is repeated several times
What are the arguments for and against artifical plant cloning
advantages
1 quick ;
2 disease-free / virus-free , stock created ;
3 plants have same feature / uniform plants created ;
4 can reproduce infertile plants ;
5 can reproduce plants that are hard to grow from seed ;
6 create whole plants from GM cells ;
7 production , not determined by seasons /
at any time / anywhere in the world ;
8 (plantlets small) can be transported easily /
grown in small space ;
9 can save rare species from extinction ;
disadvantages
Against
10 expensive / labour intensive , process ;
11 process can fail due to microbial contamination ;
12 all offspring susceptible to same ,
pest / disease /
named environmental factor (e.g. drought) ;
13 no / low / little , genetic variation ;
Give an example of a natrual clone in vertbrates
Monozygotic twins
Explain the process of artifical embryo twinning
- Egg cell with desirable traits is extracted from animal and is fertilised with sperm with desirable characteristics in a petri dish
- Fertilised egg is left to divide forming an embryo in vitro
- individual cells from embryo are separated and placed in separate Petri dishes, allows more embryos to form
- implanted in female animal
- embryos develop in surrogates and when offspring are born all of them are genetically identical
Give examples of natrual cloning in invertibrates
Hydra: produce buds on side of the body which can form into new hydra
Starfish: can generate entire starfish from fragments of their body
Explain the process of somatic cell nuclear transfer (SCNT)
- A somatic cell is taken from sheep A (or animal A) and the nucleus is extracted
- An oocyte (unnucleated egg cell) is taken from sheep B or animal B, its nucleus is removed to form an enucleated oocyte
- Nucleus from sheep A is inserted into an enucleated oocyte from sheep B
- Nucleus and enucleated oocyte are fused together using an electric shock and stimulated to divide by electrofusion, this produces an embryo
- Embryo is implanted into a surrogate mother and a lamb is born and is a clone of sheep A
Why is the clone made in somatic cell transfer not fully identical
In enucleated egg cell there is still mitochondrial DNA
What are the uses of animal cloning
- Can be used for research purposes, for example, can test drugs on cloned animals, as they are all genetically identical, genetic differences are removed
- Therapeutic cloning: clone yourself, obtain stem cell, and this means that you won’t reject your own cells (NOT allowed though)
- Used in agriculture so farmers can increase the number of animals with desirable characteristics to breed from
- Some animals have been modified to produce a useful substance (for example a goat has been genetically modified to produce a beneficial protein in milk could be cloned
- cloning can be used to save endangered animals from extinction
What are the arguments for and against animal cloning
for
- Desirable genetic characteristics are always passed onto clones
- Animals can be cloned any seasons, so you wouldn’t need to wait for breeding seasons
- can help us develop new treatments for disease
- provides a way of growing infertile animals
- can increase the number of rare animals and endangered populations which helps preserve biodiversity
Against
- Undesirable characteristics can be passed onto clones
- no genetic variability so a single disease could kill all of them
- production of clones is time-consuming and expensive
- un ethical as clones may not live as long
- using cloned human embryos as a source of stem cells is controversial some people say ts destroying human life
What is meant by the term biotechnology
use living organisms (yeast or bacteria) or parts of living organisms (enzymes) to produce food, drugs or other products
Why do we use living organisms and parts of living organisms in industrial processes
- can be grown any time of year
- they are cheap
- due to their short life cycle, they grow rapidly
- ideal growth conditions (pH, o2 levels etc) can be easily created
- can genetically engineer them to carry out reactions they wouldn’t normally do
- no welfare or ethical conditions issues to consider
- products easy to isolate
How is biotechnology used to make bread
- Yeast respires aerobically, so the Co2 it produces is used to make bread used
- the yeast usually used is called Saccharomyces cerevisiae
Commerial process
- active yeast is added to flour and is left in warm environment to prove
- Dough is knocked back, kneaded and allowed to rise again
- cooked in hot oven so co2 bubbles expand, causing it to rise further
How is biotechnology used to make beer
In beer, yeast respires anaerobically
-this produces ethanol
Commercial process
-Malting: barley germinates, enzymes are produced that break starch into sugars for yeast to respire
-Mashing: malt mixed with hot water, enzymes break down starch producing wort;
Fermentation happens
Beer is conditioned for 4-29 days
Beer is then filtered and pasteurised
How is biotechnology used to make cheese
Cheese making invoices lactic acid bacteria
-converts lactose in milk into lactic acid which makes it turn sour and contributes to it solidifying
Commerical process
Milk pasteurised - heated to 95°C for 20 seconds to kill off natural bacteria
Milk is homogenised – fat droplets evenly distributed
Bacteria and chymosin enzyme are added
-Originally we use to use rennet which contains chymosin from the lining of calves stomach but now yeast have been genetically modified to produce the enzyme
Milk separates into solid curds and liquid whey (coagulation)
How is biotechnology used to make yoghurt
Involves use of lactic acid bacteria to clot the milk and cause it to thicken
Commercial process
- milk pasteurised by heating
- Add bacteria culture and incubate (Lactobacillus)
- Sample it
- Then you can add flavours, colours
How is biotechnology used to make food (single cell protein)
- Micro-organims can be used to proudce proteins for human consumption
- Mycoprotein is used in quorn
- the fungus used to proudce the protein is called Fusarium venetanumn
How does it work
- single celled fungus grown in large fermenters using glucose syrup as food
- then itrs combined with albumen
- compressed and formed into meat subsituates
What are the pros and cons of using micro-organisms in food production
Advantages
- Microorganisms can be down quickly and cheaply therefore production costs are low
- Can be cultured anywhere, which means food source in places where rearing livestock is difficult
- single celled protein is considered healthier compared to animal protein
Disadvantages
- have to make sure food does not become contaminated with unwanted bacteria
- people may not like idea of eating food that has been grown using waste products
- single celled protein may not have same flavour or texture as meat
- if single celled protein is consumed in high quantities, health problems could be causes due to high levels of uric acid produced
How is biotechnolgy used in penicillin production
- Fungi from penicilium genus produce pencillin in times of stress, this is to stop bacteria from growing and competing for resources
- The fungus penicillium chrysogenum
- Batch culture and penicillin is produced when population reaches a certain size
How does it work
- geown in fermenters for about 6 days
- peniclin is then produced
- it is extracted and purified
How is biotechnolgy used to make insulin
-made by genetically modified bacteria
How it words
- human gene for proudcing insulin is inserted into plasmid using a vector
- this is then grown in a large scale
- insulin prudced is then collected and puified
- process is continous
What is bioremediation and how does it use biotechnology
- use of micro-organisms to remove polluanats
- examples include using microorangnims to clean soil and underground water
- microorganims then convert toxic substances into less harmful substances
How does it work
- stimulate growth of microorganism that uses contaiminent as food, by ensuring it has the right water, o2, pH temeprarture levels
- the microorgamims multiply and divide
- this will then break pollutants into less harmful products
- if conditions are suitible they are modified
- if it can’t be treated in-situ then it can be treated ex situ
What does metabolite mean
any substance prodcued by the metabolism of an organisms
For example in aerobic respiration the metabolite is co2
What are primary and secondary metabolites
Primary metabolites are produced by the organisms as part of its natural growth, so the conc of metabolite matches population size (for examples enzymes, ethanol. lactate etc) produced in continuous
Secondary metabolites: Not produced during natural growth, and conc does not match population size, this means it is harder to harvest. (penicillin, codeine, morphine) produced in batch
What is a culture
a population of an microorganism that’s been grown under controlled conditions
What are the two main methods of ferementation
Batch: grown in individual batches and then removing them to put in another batch(closed culture)
Continuous: grown without stopping, nutrients are pin and waste products are removed at a continuous rate
Why do we need to keep conditions in a fermenter at the optiumn
-maximises yield of micro-organisms and desirable products
What are the 5 factors that need to be controlled in a fermentation vessel
pH: monitored by pH probe, why?- because enzyme activity is affected by changes in pH, if at optiumn rate of reaction is high, so high yield
Temperature: monitored by temp probe. Why?- because enzymes may denature at high temps, so you need to balance rate of reaction and temp. To cool it down it is surrounded by a cooling jacket
Oxygen supply: for aerobic respiration, sterile air is pumped in so microorganisms can always respire to provide energy for growth
Nutrient concentration: Why?_ increases yield as microorganisms will always have access to nutrients needed for growth. How?- a motor stirs the mixture that circulates the medium around the vessel
Prevent contamination: Why?- don’t want other microorganisms being cultured, which means desirable microorganisms would have to compete. How?_ vessels are sterilised with steam to kill any unwanted micro-organisms
Explain the 4 stages of the growth curve (closed system)
- Lag phase: Population size increases slowly because organisms are adjusting to their surroundings. They are doing things like transcription, translation, growing, making enzymes so they can reproduce
- Exponential phase (log phase)- population size increases rapidly because conditions are favourable for reproduction, (lots of space, nutrients), population doubles every generation
- Stainonary phase: population size stays stable, as reproductive rate= death rate. Micro-organisms die because there is not enough food, or toxic waste builds up killing them
- Death phase: death rate is higher than the reproductive rate. This is because food is scarce, waste products are at toxic levels, sometimes we may prolong the death phase to make more secondary metabolites by adding glucose
Give examples of aseptic techniques
Washing hands thoroughly
Disinfecting work surfaces with disinfectant or alcohol
Wearing gloves and goggles
Working close to a lit Bunsen burner (this creates an updraught of air so prevents contamination from micro-organisms in air)
Flaming equipment (to kill microorganisms or create updraughts)
Sterilising or disposing of all used equipment
How do you culture micro-organisms in a lab
Sterilise the inoculating loop in the Bunsen burner flame
Remove the plug and flame the neck of the culture tube
Take a sample from the culture tube using the inoculating loop
Flame the neck of the culture tube again before replacing the plug
Wipe the end of the loop gently on the surface of the agar
Sterilise the loop again
Tape the lid of the petri dish
Incubate at 25°C for 24 hours
What is meant by the term immobolised enzymes
-an enzyme that is attached to an insoluble material to prevent mixing with the product
What are the three main ways that enzymes can be immobilised
- Encalpuslated in jelly like algiante beads, which act as a semi peremable membrane
- Trapped in a silica gel matrix
- Covalently bonded to cellouse or collagen fibres
How are immobilised enzymes used to convert lactose into glucose and galactose?
- Fresh milk can be ran over immbolised lactase to produce lactose free dairy products
- because some people can’t digest lactose
How are immobilised enzymes used to produce semi-synthetic penicillins
- Semi syntehtic peniclin is proudced which has same properties an natrual penicilin
- they are effective against penicilin resistent organims
- the immbolsied enzyme used is penicllin acylase enzyme
How are immobilised enzymes used to covert dextrins into glucose
- glucose used in industry to sweeten or thickin foods
- starch is broken down into dextrins
- glucoamaylse (immbolised nezymes) breaks dextrins into glucose
How are immobilised enzymes used to convert glucose into fructose
- Fructose is more sweeter than glucose
- using fructose means less sugar is needed to obtain the same level of sweetness
- immbolised enzyme glucose isomerase is used to do this on an industrial scale
How are immobilised enzymes used to produce pure samples of L amino acids
- Most amino acids needed in the human body need to be in the L form
- scientist synthesise amino acids but end up with the L and D versions of them
- immbolised enzyme aminoacylase is used to separate them
How are immobilised enzymes used to convert acrylonitrile to acrylamide
- Acrylamide is usually used to produce synthetic polymers (plastics)
- in industry immobilised nitrilase is used to convert acrylonitrile to acrylamide
What are the advantages and disadvantages of immobilised enzymes?
Advantages
- Can be reused, which reduces the cost of the reaction
- product isn’t mixed with enzymes, so no need to spend time and money separating them
- they are more stable than free enzymes, as they are less likely to denature in high temps of extremes of pH
- more reliable
- can be manipulated to fit certain processes
Disadvantages
- Extra equipment is needed which can be more expensive to buy
- immbolised enzymes are more expensive than free enzymes
- immobilisation of enzymes can lead to a reduction in enzyme activity because they cant freely move
- Higher initial costs of bioreactor
