Cloning and Biotechnology Flashcards

Question

What is different about leaf cuttings?

Answer 1

- You remove a complete leaf and scoring large veins on the lower leaf surface, and placing that in a growth medium with a warm and moist environment. Once roots have formed, you can plant in soil.

Answer 2

- A series of techniques used to grow cells, tissue or organs from a small sample of cells or tissue. - Carried out on a nutrient medium under sterile conditions. - Used commercially to produce large numbers of new plants in micropropagation.

Answer 3

Growing large numbers of plants from meristem tissue taken from a sample plant, using tissue culture. *Tissue culture usually gets cells/tissues from a plant, places them in culture to multiply + differentiate, allowing a new plant to grow, which is then rooted in soil to produce one plant. Micropropagation is a technique which uses tissue culture, to produce lots of cloned plants. When the cells divide in the culture to one large ball of cells, they are seperated into small clusters of cells (subcultured), each which form a new plant. In tissue culture and micropropagation, meristem cells are usually used.

Answer 4

1) Leaf / shoot/ meristem tissue, known as explants, are cut into small pieces. Meristem tissue is usually used as it free from viral infection. 2) Explants are then sterilised using bleach/alcohol to kill any bacteria or fungi which would thrive in the conditions supplied to help the plant grow well. 3) Place sterilised explants in a sterile aseptic growth medium containing nutrients like glucose, amino acids + phosphates. They also contain varying concentrations of auxin and cytokinin which stimulate explants to divide by mitosis to form a callus. 4) The callus is then divided into a large number of small clusters, each made of undifferentiated cells. 5) These small clusters are encouraged to grow divide and differentiate into different plant tissues. This is done by moving the cells for different growth media. The concentration ratio of auxin to cytokinin is used to control which plant tissues will develop. 6) 100 auxin: 1 cytokinin ratio stimulate root formation. 4 auxin: 1 cytokinin ratio stimulate shoot formation. 7) When plantlets, transfer to sterile soil (in greenhouse) to grow.

Answer 5

A form of asexual reproduction which involves joining the shoot/scion of one plant to the growing stem of another plant. *How is grafting a form of asexual reproduction? He said it wasn't and to take it as a seperate concept, not part of artificial vegetative reproduction.

Answer 6

- Relatively rapid reproduction (faster than from a seed) = tissue culture is much faster than cuttings, but cuttings in general is a fast method of reproduction. - Backup to sexual reproduction (plant may have lost ability to reproduce sexually/few individuals of plant specie) - Clones are genetically identical to parent plant = ∴ will display same desirable characteristics. - The unusual combination of characteristics a plant has due to selective breeding or genetic modification can be retained without the risk of losing that combination in sexual reproduction. - Uniform phenotype/characteristics means easier to grow and harvest - e.g. same height so can be cut at a specific height for all the genetically identical plants - If an apical bud is used as an explant and aseptic technique is used, new cloned plant formed from tissue culture will be free from viruses as it contains meristem.

Answer 7

This is the location where shoot growth occurs, usually found at the end of the a shoot.

Answer 8

- Labour intensive - Expensive to set up facilities to perform successful tissue culture. - Can fail due to microbial contamination - Cloned offspring genetically identical = little or no variation (mutation is the only way for variation to occur) susceptible to same pests or disease which would spread rapidly.

Answer 9

- A stem section of a woody plant (scion) is cut into a wedge - The root stock is cut to match the scion - The vascular tissue is lined up - Binding tape is wrapped around the graft area to hold it in place

Answer 10

Tissue culture: - Requires warm temperatures - Genetically identical cloned plants are produced - it’s Thousands of clones can be produced from one plant - More expensive - More advanced technology - Slower method to make cloned plants - Only require a few cells ``` Take cuttings: - Requires warm temperatures - Genetically identical cloned plants are produced - Cheaper - Less advanced technology required - Older plants can be used Faster method to make cloned plants - Needs hormones for root growth to speed up process - Requires leaves ```

Answer 11

Tissue Culture - Thousands of clones can be produced from one plant - More expensive - More advanced technology - Slower method to make cloned plants - Only require a few cells ``` Take cuttings: - Cheaper - Less advanced technology required - Older plants can be used Faster method to make cloned plants - Needs hormones for root growth to speed up process - Requires leaves ```

Answer 12

Most of the leaves are removed from the cutting to reduce water loss. Otherwise, the cutting could dry out very quickly and not grow.

Answer 13

It is important to leave some leaves on cuttings so that photosynthesis occurs to make glucose so new roots can grow.

Answer 14

The cuttings could overheat and lose water; damages very young leaves.

Answer 15

Reproductive cloning is used to produce genetically identical clone from a donor animal using embryo splitting/twinning or somatic cell nuclear transfer.

Answer 16

- To increase the number of farm animals with a desirable characteristic (produced from artificial selection/selective breeding or genetic modification) - Scientists can use cloned animals for research purposes - testing drugs etc. - Save endangered animals from extinction by cloning new individuals.

Answer 17

- Embryo twinning/splitting | - Somatic cell nuclear transfer(SCNT)

Answer 18

1) A zygote (a fertilized egg) is created by in vitro fertilization (fertilization outside a living organism, i.e. in a petri dish) 2) The zygote is allowed to divide by mitosis to form a small ball of cells. 3) The cells are separated and allowed to continue dividing. 4) Each small mass of cells formed is placed into the uterus of a surrogate mother. 5) The embryos continue to develop inside the surrogate mothers and eventually the offspring are born. 6) The offspring are genetically identical to each other. The precise genotype and phenotype of the offspring produced will depend upon the sperm and egg used so they will not be known until the offspring is born

Answer 19

1) Differentiated somatic cell is taken from an adult sheep (e.g. udder cell) 2) A ewe is superovulated (using FSH) and egg cells are collected from the ovary / washed out of the oviduct 3) The nucleus is removed from the somatic cell and placed in an enucleated egg cell – an egg cell which has had its nucleus removed. 4) An electric shock is given to fuse the nucleus and the empty egg cell 5) This cell is then placed in a tied oviduct of a ewe to develop into an embryo (in culture) 5) The embryo is then recovered from that ewe and treated with hormones. 6) It is then placed into a surrogate mother’s uterus where it will develop and eventually an offspring will be born. 7) The offspring will be genetically identical to the sheep, which provided the nucleus to be placed in an enucleate egg cell.

Answer 20

The phenotype of the offspring is known before cloning starts. This is not possible with embryo twinning. - This is the only method that allows cloning of an adult - embryo twinning does not clone adults because the cells of the embryo are formed from random fertilisation which results in the mixing of genetic information from the egg and the sperm - it allows clones of the offspring to be made.

Answer 21

- Mitochondrial DNA remains in the enucleated egg cell | - Cloned individual has DNA from the nucleus donor and mitochondrial DNA from the egg donor

Answer 22

Non-reproductive cloning is the production of cloned cells and tissues for purposes other than reproduction.

Answer 23

Therapeutic Cloning

Answer 24

- New tissues can be grown to replace dead or damaged tissues - cloned cells have been used to repair damage to nervous tissue in mice (i.e. repair to spinal cord after paralysis) and to regenerate tissue such as that of the heart muscle (after heart attack) nervous tissue in mice (i.e. spinal cord after paralysis). Skin can be grown in vitro to act as a graft over burned areas - Whole new organs can be grownto replace damaged or diseased ones.

Answer 25

- We can increase the number of farm animals with a desirable characteristic, as clones retain the same genotype and phenotype of the animal that is cloned. - Using genetically identical embryos and tissue for research allows the effect of genes and hormones to be assessed with no interference from different genotypes. - Testing medicinal drugs on cloned cells and tissues avoids using animals or people for testing - Cells and tissues grown from the patient's own cells are genetically identical to the donor so can be used in repairing damage caused by disease or injury, without rejection* - Individuals from an endangered species can be cloned to increase numbers *e.g. taking stem cells, cloning them by therapeutic cloning, and allowing them to diffferentiate into the correct cells and tissues)

Answer 26

- Lack of genetic variation, means all members of the herd are susceptible to certain pests or diseases. - Animals may be produced with little regard for their welfare, which may have undesirable side affects such as meat-producing chickens that cannot walk - The success rate of adult cell cloning is very poor and the method is a lot more expensive than conventional breeding. (DOES THE TERM 'ADULT CELL CLONING' REFER TO BOTH EMBRYO TWINNING AND SCNT?) - Cloned animals may be less healthy and have shorter life spans. - There are ethical issues regarding how long the embryo survives and whether it is right to create a life simply to destroy it. - This does not help increase genetic diversity.

Answer 27

The use of living organisms or parts of living organisms in industrial processes. this could be to produce food drugs or other products

Answer 28

- Healthcare and medical processes – e.g. producing drugs (e.g. insulin) with microorganisms and gene therapy - Agriculture – micropropagation of plants (tissue culture) and GM crops (e.g. with drought tolerance) - Industry – using microorganisms to produce enzymes - Food science – developing foods with better taste, nutrition, texture or appearance

Answer 29

- M = cheap + easy to grow - Production process of molecules using M can occur at lower temperatures = saves fuel + reduces costs. - Production process of molecules using M can occur at normal atmospheric pressures = safer - Production process not dependent on climate - so can occur anywhere in the world as long as the required resources and suitable equipment are available. - M have short life cycle + reproduce quickly = large population can grow quickly inside the reaction vessel/fermenter. - M can be genetically modified easily = specific production process is can be achieved - fewer ethical considerations when using M - Product made by M are released into the surrounding medium = easy to harvest - Product made by M are often more pure or easier to isolate = lower downstream processing costs - M can be fed using by-products from other food industries e.g. starch, waste water or molasses (easy to maintain M, low economic cost)

Answer 30

- Beer production + Making bread rise | - Production of cheese and yoghurt

Answer 31

- Milk which has undergone fermentation by L. bulgaricus + S. thermophilus. - These convert lactose --> lactic acid. - Aciditiy of lactic acid denatures milk protein = causing it to clot/coagulate - Bacteria partially digest milk also = making it easy to digest - Bacteria like L. acidophilus may be added as probiotics (bacteria which may benefit human health, by improving digestion of lactose, improving gastrointestinal health).

Answer 32

- Milk which has undergone fermentation by L. bulgaricus + S. thermophilus. - These convert lactose --> lactic acid. - Once acidified, milk is mixed with rennet, which contains the enzyme chymosin. - Rennin coagulates the milk protein (casein) in the presence of calcium ions. - Kappa-casein, which keeps the casein in solution, is broken down by chymosin, making casein insoluble. - The casein is precipitated by the action of calcium ions, which bind the molecules together. - Resulting solid, known as curd, Is separated from the liquid component (by by cutting stiring and heating) - the bacteria continue to grow producing more lactic acid - the Curd is then pressed into mould treatment while making impressing the curd determines the characteristics of the cheese. - Bacteria like L. acidophilus may be added as probiotics (bacteria which may benefit human health, by improving digestion of lactose, improving gastrointestinal health).

Answer 33

SCPs (aka mycoprotein) are proteins manufactured by microorganisms that can be directly used as food. A microorganism which produces a type SCP is the fungus Fusarium venetatum. An example of an SCP or mycoprotein is Quorn. They can produce proteins with a similar amino acid progile to animal and plant protein and they have no animal fat or cholesterol = suitable substitute for meat/a healthier option than meat.

Answer 34

Anaerobic respiration of yeast (S. cervisae, a microorganism) in the presence of glucose, produces CO2 and ethanol. Fermentation of glucose by yeast is used in used in making bread, by placing the dough in a warm place for 3 hours, so when the yeast respires anaerobically, CO2 is produced to make bread rise. When dough is cooked/baked, any alcohol produced in fermentation evaporates.

Answer 35

Anaerobic respiration of yeast (S. cervisae, a microorganism) in the presence of glucose, produces CO2 and ethanol. Fermentation of glucose by yeast is used in beer production, as it produces the ethanol needed. The yeast is added to dried germinating barley grains (malting). The grain converts starch to maltose, which is respired by the yeast anaerobically to produce ethanol and CO2

Answer 36

- Penicillin production = the fungus, Penicillium notatum, produce an antibiotic called penicillin to stop bacteria from growing + competing for resources. The fungus is now grown on a large scale, in stressful to produce this antibiotic, which is collected and purifies to be used as drug against bacteria in the body. - Insulin production = Bacteria are genetically modified to produce insulin. The bacteria is then grown in an industrial fermenter on a large scale, to produce insulin which is then collected and purified for use in the body.

Answer 37

- Protease and lipase produced by the bacteria, B. licheniformis, is used in washing powders - Pectinase produced by A. niger is used to extract juice from fruit. - A. niger (and A . oryzae) produces lactase which breaks down lactose so that lactose-free milk is available

Answer 38

- Biogas (mix of CO2 and methane) produced by anaerobic bacteria (decomposers) - Bioremediation = a variety of bacteria and fungi remove pollutants, like oil and pesticide from contaminated sites like waste water, by using them as a food source and breaking them down into less harmful products. May be provided with extra nutrients so they grow and multiply quicker.

Answer 39

- Protein production by M is faster than by animals/plants. - Biomass has very high protein content = good source of protein - Production can be increased and decreased according to demand - No animal welfare issues - Protein contains no animal faster or cholesterol - M can be easily genetically modified to adjust the amino acid content of the protein - M can be fed using waste/by-products - Production independent of seasonal variation - Does not require a lot of land

Answer 40

- Some people may not want to eat fungal protein all food that has been grown on waste - Protein needs to be isolated from the fermenter which contains the materials in which they grew and microorganisms. - protein has to be purified to ensure it is uncontaminated (biomass contains lots of nucleic acids that need to be removed) - Amino acid profile may differ from traditional animal/plant protein e.g. deficient in certain amino acids - Conditions for growth of M are also ideal for growth of pathogenic organisms = Need to insure culture is not infected/contaminated. - Palatability - protein does not have taste or texture of traditional protein sources

Answer 41

- Selective breeding - Genetic modification - Cloning through embryo-splitting + micropropagation - Using enzymes in industrial processes - Immunology

Answer 42

Vessels used for commercial drug production. The growing conditions for microbes inside of these vessels are controlled to ensure the best possible yield of product.

Answer 43

- Temperature (too hot = enzyme denaturation, too slow = limited microbe growth) - Nutrient availability (needed for growth of microorganisms) - Oxygen availability (most microorganisms respire aerobically) - pH (extreme pH restricts enzyme activity = denaturation) - Concentration of product – (if product builds up = may affect synthesis process)

Answer 44

- It must be sterilised using a superheated steam.

Answer 45

- Water jacket outlet - Water jacket inlet - Air Inlet - Air Outlets - Outlet tap - Mixing blades/Impellers - Motor - Electronic probes - Inlet - Pressure vent

Answer 46

Prevents any gas build-up.

Answer 47

Provides sterile air needed for aerobic fermenters, which contain microorganisms that respire aerobically using oxygen in oxidative phosphorylation. Once the air enters the air inlets, it is released into the mixture as air bubbles through the air outlet.

Answer 48

Mixes the contents of the fermenter evenly (i.e. Mixes microorganism with substrate)

Answer 49

The water jacket inlet and outlet allows the circulation of water around the fermenter to regulate temperature. Allows cooling (as respiration produces heat) To maintain optimum temperature for enzyme action.

Answer 50

Prevents buildup of pressure due to the release of gaseous products.

Answer 51

Rotates the mixing blades.

Answer 52

Drains the fermenter when necessary.

Answer 53

Necessary for the addition of nutrients to synthesise amino acids the microorganism needs.

Answer 54

Needed for measuring oxygen pH and temperature levels in the fermenter. For example, if pH changes, indicates the need for a buffer.

Answer 55

To prevent contamination.

Answer 56

Batch fermentation | Continuous fermentation

Answer 57

- Nutrients are added and products are removed at regular intervals (I.e. continuously) = causes a high microbe growth rate. Volume in the fermenter is kept constant. - The growing conditions can be difficult to maintain/kept constant (temp, PH, oxygen, nutrients). - Very inefficient as fermenter is in constant use but if contaminated huge volumes will be lost. - Useful in producing primary metabolites such as proteins like human insulin from GM E. coli.

Answer 58

- The microorganism starter population (so population has to be established) is mixed with a set quantity of nutrients, grown for a set time and then the products are removed. - Produces secondary metabolites (e.g. antibiotics like penicillin) – but not very efficient as fermenter not in use all of the time. - Short log phase, then the metabolite is produced during stationary phase (after the growth phase). - Nutrients are only added at start and decrease over time (so growth rate of microbe is slower). - Build-up of waste products causes reproduction to drop. - If batch contaminated it can be discarded, without huge losses.

Answer 59

- Stress | - This is done by using a high population density of microorganisms with limited nutrient availability in the fermenter.

Answer 60

- Primary metabolites are the products synthesised by the microorganism during their normal metabolism, when they are actively growing and hence primary metabolites are produced in the growth phase (when the population of microorganisms are being established i.e. log and lag phase). It is initiated when the nutrients required are present in the medium for the microorganism to grow. - Secondary metabolites are the product synthesised by the microorganism that are not essential for their growth, development and reproduction. These metabolites help protect the nutrient supply from being used by competitors. Secondary metabolites are produced in the stationary phase (so once the population of microorganisms have been established).

Answer 61

- P: AAs, enzymes, proteins nucleic acids | - S: Antibiotics like penicillin

Answer 62

Ensures sterile conditions are maintained. This is important because, otherwise the nutrient medium would support the growth of unwanted microorganisms which would: - compete with the culture microorganisms for nutrients and space - reduce the yield of useful products - spoil the product - -produce toxic chemicals - destroy the cultured microorganisms and their products.

Answer 63

It need to be discarded

Answer 64

- There is a lag (log + lag phase i.e. growth phase) in penicillin production. This indicates the fungus was in the growth phase during this lag and as no penicillin was produced, this tells us that the fungus population has to be established first - the fungus has to be in the stationary phase for penicillin to be produced. Therefore as secondary metabolites are only produced in the stationary phase, penicillin must be a secondary metabolite. - Secondary metabolites are produced in batch fermentation/culture, so this was the method used.

Answer 65

Gene for human insulin combined with plasmid of E.coli (acts as a vector) before inserting the E.coli. The E.coli are then grown in culture to produce insulin.

Answer 66

- Water availability - Suitable temperature - Suitable pH - Oxygen availability - Nutrient availability

Answer 67

- Uses natural systems - Less labour/equipment required - Treatment in situ - Few waste products - Less risk of exposure

Answer 68

- Treatment time is typically longer than that of other remediation technologies. - If the process is not controlled it is possible the organic contaminants may not be broken down fully resulting in toxic by-products that could be more mobile than the initial contamination.

Answer 69

A closed culture is a culture which has no exchange of nutrients or gases with the eternal environment (batch cultures have a closed culture). No waste products are removed either.

Answer 70

The population of microorganisms follow a standard growth curve. (pg.260 in book, pg.243 in CGP) *Doesn’t both continuous culture and batch culture produce primary metabolites because they both have a growth phase. Continuous culture will not produce secondary metabolites because it will not reach a stationary phase as nutrients are always being added. If this is right, read through notes and make changes (only a few places).

Answer 71

- Lag phase - Log (exponential) phase - Stationary phase - Decline or death phase (in closed population)

Answer 72

- Only a few individuals | - Low rate of reproduction/growth as individuals are acclimatising to the environment

Answer 73

- Plenty of resources for all microorganisms - Good environmental conditions as organisms have adjusted to it. - Rate of reproduction is higher than mortality, so population size grows rapidly

Answer 74

- The population size has levelled out at the carrying capacity - Increasing number of microorganisms means lack of nutrients available and waste products start to build up, so number of individuals dieing increases until rate of reproduction and mortality are equal (no population growth)

Answer 75

- Fewer resources available i.e. becomes very scarce (increased competition) - Waste products build up (high concentrations may be lethal) - The rate of mortality is greater than reproduction rate, so population size decreases.

Answer 76

Adjusting to growing conditions (e.g. O2 levels, availability of nutrients, pH levels) and synthesis of enzymes is required which takes tim.

Answer 77

Competition with other bacteria (if not a closed pure culture), nutrient, O2 & space avail., pH

Answer 78

Adding nutrients would not affect growth at this stage as the cells are active but not reproducing

Answer 79

The graph line would curve upwards as population size would increase.

Answer 80

Temperature & pH affects enzyme activity (denature enzymes; cell metabolism ceases). Oxygen is required for aerobic respiration (to release energy for culture/microbe growth)

Answer 81

an enzyme that is held in place in not free to diffuse through the solution.

Answer 82

They catalyse the reaction by binding to substrates and converting it into the product. The enzyme is not used up in the reaction.

Answer 83

Enzymes remain in suspension/in the final solution when the reaction is completed therefore the product must be isolated from the enzymes before use - this could be expensive.

Answer 84

- Enzymes produce fewer by-products - Lower optimum temp compares to chemical catalysts (less expensive) - No need to grow whole organisms in order to make a product – requires sometimes only one isolated enzymes.

Answer 85

Use immobilised enzymes - these are held in position so that they do not mix freely with the substrate so will not be present in the final solution.

Answer 86

- Enzymes do not mix with product = extraction/purification costs lower - Enzymes can easily be reused - Easier to carry out continuous processes as there are no cells requiring nutrients or producing waste products that would otherwise need to be removed, only enzymes present. - Enzymes are surrounded by immobilising matrix, which protects it from extreme conditions - so higher temperatures or wide pH range can be used without causing denaturing.

Answer 87

- If contamination occurs, current reaction mixture must be discarded – expensive + loss of product. - Setting up the immobilised enzyme process is more expensive. - Immobilised enzymes are usually less active than free enzymes (not mixed together as well) = making the process slower.

Answer 88

- Adsorption - Covalent bonding - Entrapment - Membrane separation

Answer 89

Enzyme molecules bound to a supporting surface by hydrophobic interactions + ionic links, with their access site exposed and accessible to substrate.

Answer 90

Clay, porous carbon, glass beads and resin.

Answer 91

- Active site of enzymes may be slightly distorted by the additional interactions to the supporting surface = this may affect enzyme activity. - Interactions and forces between enzyme and supporting surface are not strong so enzyme may become detached and leak into the reaction mixture.

Answer 92

Enzymes are bonded to the supporting surface using strong covalent bonds. They are bonded using a cross linking agent which may also link them in the chain.

Answer 93

Production of covalent bonding could be expensive and can distort the enzyme active site = reducing enzyme activity, however the enzymes are much less likely to become detached and leak into the reaction mixture .

Answer 94

Enzymes trapped in a matrix by a network of e.g. cellulose fibers or gel bead that does not allow free movement of enzymes. These enzymes are unaffected by entrapment and remain fully active. However, the substrate molecules must be small enough to diffuse into the entrapment matrix and the product molecules must be small enough to diffuse out.

Answer 95

Access to enzymes may limit the reaction.

Answer 96

Enzyme molecules separated from the reaction mixture by a partially permeable membrane. The substrate and product molecules are small enough to pass through the partially permeable membrane by diffusion.

Answer 97

Access to enzymes may limit the reaction

Answer 98

``` Glucose isomerase Glucoamylase Penicillin acylase Lactase Aminoacylase Nitrile Hydratase ```

Answer 99

Method of immobilisation: Entrapment, adsorption and covalent bonding Substrate: Penicillin Product: Amino penicillanic acid Use:: Amino penicillanic acid is the base molecule used to produce a range of penicillin–type antibiotics (including amoxicillin and ampicillin). Useful because some penicillin-resistant bacteria are not resistant to these synthetic types

Answer 100

Method of immobilisation: Adsorption or covalent bonding Substrate: Glucose + xylose Product: Fructose + xylulose Use: To produce high fructose corn syrup

Answer 101

Method of immobilisation: entrapment (alginate beads) Substrate: Lactose Product: Glucose and Galactose (by hydrolysis) Use: To produce lactose-free milk. Milk provides calcium to prevent the development of weak bones and osteoporosis therefore it is important in a diet. This allows lactose intolerant people to still be able to get access to the calcium in milk.

Answer 102

Method of immobilisation: adsorption Substrate: N-acyl-amino acid Product: L-amino acid by removing acyl group from the nitrogen on the N-acyl-amino acid. Use: L-amino acids are the base molecules for the synthesis of pharmaceutical and agrochemical compounds like animal feed, pesticides and herbicides

Answer 103

Method of immobilisation: Covalent bonding Substrate: Dextrins or maltose Product: Glucose (When starch hydrolysed to glucose, dextrins, which are short polymers of glucose, may be formed. Glucoamylase further hydrolyses dextrins to glucose). Use: Digest sources of starch like corn, used in fermentation processes including conversion of starch pulp to alcohol used to produce gasahol – an alternative fuel for motor vehicles. Also used to make high fructose corn syrup.

Answer 104

Method of immobilisation: Entrapment Substrate: Nitriles Product: Amides Used for: Conversion of acrylamide to polyacrylamide, which is a plastic used as a thickener. Polyacrylamide is mainly used in the treatment of water as it helps stick contaminants together so they are precipitated out and easy to filter out of the water. Used to make gel for electrophoresis + involved in paper-making.