M6 C22: cloning and biotechnology Flashcards
what is a natural clone?
genetically identical copies of something
what are some examples of natural clones
mitosis in cells
yeast budding
binary fission
advantages of natural clones?
don’t need a mate
pass on advantageous alleles quicker
conditions that are good for parents are good for the offspring
disadvantages of natural clones?
lack of variation
could lead to wipe out by a pathogen
offspring overcrowded
selection not possible
susceptible to change
what is vegetative propagation?
plants that can reproduce asexually by cloning as they have many cells that retain the ability to differentiate
what are some examples of vegetative propagation?
runners- strawberry plants, spider plants
suckers- old branch may die and the new branch replaces it
Bulbs – underground stem
Tubers – underground stem. One potato can grow into one or more plants.
why is it importsnt to use thin slices of organisms when viewing plants under a microscope?
In preparations several cells thick the light must travel through the other cell layers, reducing the quality of the image, and at low magnifications several cells could a layered image of several cells at once.
what is tissue culture?
groeing new tissues, organ or plants from certain tissues cut from sample plants
what is micro propagation?
growing a large number of plants from meristem tissue taken from a sample
when is it useful to use microproagation?
The desirable plant doesn’t:
Produce many seeds
respond well to natural cloning
Rare
GM or selectively bred
Needs to be pathogen free
how is micro propagation done?
cells took from ex plant
sterilized before placed onto growth medium which contains glucose, amino acids, phosphates
they form a callus culture
divides to produce lots of undifferentiated cells
transferred to a new medium to grow with hormones
transferred to compost once stable
what are advantages of micro propagation?
Rapid compared to growing from seed
Disease free plants
Increase numbers of rare plants
Large numbers of seedless plants (bananas and grapes)
Naturally infertile plants can be grown (e.g. Orchids)
what are disadvantages of micro propagation?
Monoculture – genetically identical (susceptible to the same diseases/growing conditions)
Expensive and requires skilled workers
Explants and plantlets are vulnerable to mould during the process
If source materials infected with a virus, all new plants are infected
what is the process of tissue culture?
root cut into small discs
root discs pressed onto a dish contasining agar jelly
kept in an incubator
callus develops and transferred to new dish of agar
after several weeks this form tiny plants which are then tranferred to a flask with nutrients
what is an example of cloning in animals?
Identical twins - a fertilised egg (zygote) splits into two.
what are some invertebrates that can clone?
Starfish can regenerate an entire organism from just a fragment of the original
Sponges and flat worms create clones as part of their natural reproductive cycle
Hydra produce small buds on the side of their bodies that eventually live independently
what is the process of artifical embryo twinning?
1- A fertilised egg (zygote) is created using IVF
2- The zygote divides by mitosis to form a ball of cells
3- Cells are separated and allowed to continue dividing
4- Each mass of cells is placed into the uterus of a surrogate mother
5- offsrping is given birth to naturally by a surrogate
what is Somatic Cell Nuclear Transfer Cloning?
The egg cell has its nucleus removed which is then fused with the nucleus of a normal cell due to an electric shock
the zygote then divides by mitosis into lots of embryo cells
the embryo is then implabted into the surrogate and then is given birth to like a natural birth
what are some uses of cloning?
Mass producing animals with desirable characteristics.
Producing animals that have been genetically engineered to produce human products
Producing human embryos to supply stem cells
what are some disadvantages of cloning?
many are born abnormally large
Health problems
Very few embryos survive until birth- can be distressing if the surrogate has a misscarriage
what are some advantages for cloning?
Desirable genetic characteristics always passed on
Infertile animals can be reproduced
Do not need to wait for breeding season
Increase population of endangered species
Develop new treatments for disease
what are some disadvantages for cloning?
Very difficult to do, time-consuming and expensive
No genetic variability – all susceptible to the same disease
Undesirable characteristics always passed on
Evidence suggests that clones may not live as long as natural offspring
what is fermentation?
Microorganisms can be grown under controlled conditions in larger fermenters
The product of fermentation is either the microorganisms itself e.g. mycoprotein, or a product produced by the microorganism e.g. insulin
what is batch fermentation?
Microorganisms are grown in batches in the fermentation vessel
Once the culture cycle is complete, the product is removed, the fermenter is cleaned and a new batch of microorganisms is grown. Process stopped before death phase and products harvested
This is known as a closed culture
what is continuous fermentation?
Microorganisms are continually grown and the products harvested thry are made during normal growth (primary metabolite)
Nutrients are added and waste is removed throughout the culturing process
how is brewing used with yeast?
Malting – barley germinates, enzymes are produced that break starch into sugars for yeast to respire
Mashing – malt mixed with hot water(55-65°C); enzymes break down starch producing wort; hops added for flavour
Fermentation – yeast added to wort; fermentation occurs; yeast eventually killed as pH lowers, ethanol builds up and oxygen decreases
Maturation – beer conditioned for 4-29 days (2-6°C)
Finishing – beer filtered, pasteurised, bottled/canned.
how does yeast respire?
Glucose -> ethanol + carbon dioxide
(sugar) (alcohol)
how is yeast used in baking?
yeast respires aerobically the carbon dioxide produced makes the bread rise.
Active yeast mixture is added to flour and other ingredients; left in a warm environment to rise
Dough is ‘knocked back’ (excess air removed), kneaded, shaped and allowed to rise again
Cooked in a hot oven so CO2 bubbles expand
Yeast cells are killed during cooking
how is bacteria used in cheese making?
bacteria are fed on lactose a sugar found in milk to produce lactic acid
Lactose -> lactic acid
what is the process of cheese being made with bacteria/
Milk is 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
Milk separates into solid curds and liquid whey
what are the curds from the milk used for?
Cottage cheese – curds are packaged and sold
Harder cheese – curds cooked in the whey and strained through a cheese cloth and may be pressed/ matured
what is the whey used for from the milk?
Whey – used in animal feeds
how is yoghurt produced?
Bacteria are fed on lactose a sugar found in milk to produce lactic acid
Lactose -> lactic acid
what is the process of yoghurt production?
Sterilisation of equipment (heat to 71oC for 20s to kill bacteria)
Pasteurisation of milk
Add bacteria culture and incubate (Lactobacillus)
Sampling
Addition of flavours, colours and packaging
Quality control and take some culture to add to the next batch
how is penicillin made?
produced by batch culture as it is only produced once the population has reached a certain size. (it is a secondary metabolite)
The fermenter is run for 6- days, it is then filtered to remove the cells
Potassium compounds are then added and the penicillin precipitated as crystals
The antibiotic is then prepared for administration as tablets, syrup or injection.
how is synthetic insulin produced?
produced by genetically modifying bacteria.
The human gene for producing insulin is inserted into a bacterium using a plasmid as a vector.
The resulting genetically modified bacteria can then produce vast quantities of insulin.
Insulin is produced using a continuous process.
what is Bioremediation?
use of microorganisms to clean the soil and underground water on polluted sites.
Microorganisms convert toxic substances to less harmful substances.
what is Single-cell protein (SCP)?
microorganisms can be used to produce proteins for human consumption as food
Many different fungi can be used to create proteins with similar amino acid profiles to that of plants and animals. They can grow on almost any organic substrate including waste including paper and whey (curdled milk after the curds have been removed)
an example of this is quorn
advantages of using microorganisms to make food for human consumption?
Production of a protein can be much faster than if made by an animal or plant
Production can be increased/ decreased according to demand
No animal welfare issues
Protein contains no animal fat or cholesterol
Microorganisms can be GM to adjust the amino acid content of the protein
Not affected by seasonal variations
Not much land is needed
disadvantages of using microorganisms to make food for human consumption
Some people may not want to eat fungal protein or food grown on waste
Need to isolate the protein from the medium it is grown in
Protein has to be purified
Culture can become infected easily due to optimum growing conditions
Different taste/texture to traditional protein source
what is biotechnology?
use of organsism in technology to make a useful prooduct
what is aseptic technique?
reduce likelihood of contamination with unwanted bacteria or fungi.
how can we ensure aseptic technique?
Washing hands
Disinfect working area
Bunsen burner operating near by ( heats air, causes air to rise and prevents air born microbes from settling)
Flaming the necks of bottles as they are opened and closed to prevent bacteria entering (also glass/metal equipment)
Only slightly lift lid on the petri dish
what is innoculation?
The act of introducing microorganism or suspension of microorganisms (e.g. bacteria) into a culture medium
What is incubation?
providing conditions for optimal growth of microbiology cultures
what is the lag phase?
where a small number of individuals reproduce
what is the log phase?
exponential growth
Ever-increasing number of individuals reproduce. The population doubles per unit time
what is the stationary phase?
Population growth declines until it remains stable with cyclic fluctuations.
what is the death phase?
Nutrients run out, waste builds up
Eventually all will die
what are some examples of limiting factors that can inhibit bacteria growth?
Food
Shelter
Light
Water
Oxygen
Accumulation of toxic waste
Disease
Predators
what are immoblised enzymes?
enzymes that cant move anywhere because they are attached and held in place by a susbstrate
advanatges of using immobilised enzymes?
can be reused
no contamination of enzymes into product
cheap to carry out
withstand higher ph / temps as the bonds and active site cant break as they are held in place
disadvanatges of using immbolised enzymes?
Specialist expensive equipment is required
Immobilised enzymes are more costly to buy, so are unlikely to be financially worthwhile for smaller industries
The rate of reaction is sometimes lower when using immobilised enzymes as the enzymes cannot freely mix with the substrate
what are 3 main methods of immoblising enzymes?
adsorption
covalent bonding
entrapment
what is adsorption?
porous support such as clay or glass beads bind to ewnxymes it has hydrophobic interactions and ionic links. active site is accessible but can be changed due to the bonds.
what is covalent bonding?
enzymes bonding onto suporting surface using strong covalent bonds could distortrt the acgtive site, expensive however is less likely to leak
what is entrapment?
enzyme trapped in gel like substance. active site not as accessible, longer process however there is no change to an active site as susbstrate has to diffuse in and out
Glucose isomerase?
Converts glucose to fructose
Produces high fructose corn syrup- much sweeter than sucrose
Often used in diet foods
Cheaper than sucrose
Penicillin acylase?
Formation of semi-synthetic penicillins e.g. amoxicillin and ampicillin
Some penicillin resistant microorganisms are not resistant to these
Lactase?
Lactose -> glucose and galactose by hydrolysis
Used to produce lactose free milk
Aminoacylase
Used to produce pure samples of L-amino acids by removing the acyl group from the nitrogen of an N-acyl-amino acid
L-amino acids are the building blocks for the synthesis of a number of:
Pharmaceutical compounds
Agrochemical compounds
Additives for food
Glucoamylase
Converts dextrins to glucose
During the hydrolysis of starch, short polymers of glucose (dextrins) are formed.
Can be immobilised on a variety of surfaces and used to digest sources of starch e.g. corn and cassava
Used also to ferment starch pulp to alcohol to produce gasohol
Also to make high fructose corn syrup
Nitrile hydratase
Converts nitriles to amides including acrylonitrile to acylamide
Acrylamide can be polymerised to form polyacryamide (plastic used as a thickener)
can be used to treat water – sticks small contaminants together so they can be precipitated and easily filtered
Also used in paper making and gel for electrophoresis
