Cloning And Biotechnology Flashcards
What are the advantages and disadvantages of asexual reproduction
Advantage:
Fast
Take advantage of resources
All offspring adapted to environment
Possible when sexual is not
Disadvantage:
No genetic variation
If environment changes, if one is susceptible, they all are
What are the two methods of cloning animals
Artificial embryo splitting
Somatic cell nuclear transfer (SCNT)
How does artificial embryo splitting occur
Eggs and sperm collected from high-value parents
In vitro fertilisation forming a zygote
Mitosis to form 16-cell embryo
Split embryo into several separate segments, implant into surrogate mothers
Offspring are genetically different from parents, and genetically identical to each other
How does somatic cell nuclear transfer (SCNT) occur
Remove diploid cells from one parent - grow in culture
Take an egg and remove the nucleus from another parent
Inject the diploid cell nucleus into the egg (diploid zygote)
Put into oviduct of a parent, culture in tied oviduct
Recover early embryo, implant into surrogate mothers uterus
Offspring produced
Why does somatic cell nuclear transfer not produce absolute clones
Offspring have nuclear DNA from nucleus donor
And
Mitochondrial DNA from donor of enucleated ovum
What are the advantages of cloning animals
Advantages: can clone large numbers of animals and quickly
- desirable animals
- endangered animals
- GM animals
- infertile animals
Can clone at any time
Can clone tissues to treat diseases
What are the disadvantages of cloning animals
Difficult, time consuming and expensive
Welfare of animals not always a priority
Genetic uniformity/ monoculture
Long term health of clones a concern - short life span
Define vegetative propagation
part of a plant is separated then develops into a new plant genetically identical
natural clones
What are rhizomes
Stems that grow horizontally underground
What are stolens/runners
Stems that grow horizontally above ground
What are suckers
Shoots grow up from buds on shallow roots
What are tubers
Large underground plant structures that act as food stores - covered in ‘eyes’ that can form new plants
What are bulbs
Underground food stores - new bulbs can develop from the original bulbs and form new plants
What are the traditional methods of cloning plants
Taking cuttings - leaf or root, use auxins as root powder
Grafting - short section of a woody plant is joined to an already growing root and stem (rootstock)
What are the disadvantages of traditional cloning methods for plants
Can’t produce large numbers
Some plants don’t reproduce well from these methods
How does grafting of plants take place
Short section of woody plant is joined to an already growing root and stem (rootstock)
Vascular tissues must be lined up
Bindings until growth is supportive
Define tissue culture
- the separation of cells of any type and their growth in/on a nutrient medium
Rapid reproduction
Large number of clones
Develop a disease free stock of plants - aseptic techniques
Small amount of parent material
Describe micropropagation by callus tissue culture
Cells taken from shoot tip with sterile forceps
Placed in nutrient agar
Split into little clumps of cells
Shoot stimulating hormones, root stimulating hormones, (auxins/cytokines)
Plantlets planted into compost
What are the advantages of cloning plants
Aided development of desirable crops. Ie high yield, pest resistance
Reproduction and survival of plants that are sterile
Predictability of the crop. E.g. known yield, taste, colour etc.
Economic benefits
Avoid waste
Whole crop ready at same time Ωzzzzzzzzzzzzzz
Define biotechnology
The use (exploitation) of living organisms or biological processes to improve agriculture, animal husbandry, food and science, medicine etc.
Why are microorganisms suitable for biotechnology
-Grow rapidly
-Ethics
-Wide range of organisms
-Prokaryotes reproduce asexually (genetically identical)
-Products are pure
-Can be grown in controlled conditions
-Independent of environment
-Gene expression is relatively simple - easily genetically engineered
-Grow at relatively low temperatures - saves energy
-Produce proteins or chemicals that can be harvested
Define generation time in biotechnology
Time taken for numbers to double
What are the advantages of using quoin as a source of protein
- can grow on waste material e.g. molasses
- quick, easy and cheap
- can culture anywhere
- healthier
What are the disadvantages of using quoin as a source of protein
- contamination by unwanted bacteria
- texture and taste is different
- health problems when eaten in large quantities
What is the growth curve
Growing bacteria or fungi in a closed culture
(Conditions are fixed, contained, no new material added, no waste product removed)
What are the phase of the growth curve
Lag phase - organisms are adjusting to environment - not reproducing yet
Log or exponential growth phase (number of cells are doubling per unit of time)
Stationary phase - nutrient levels decrease, waste products increase, organisms die at the same rate as reproduction
Death or logarithmic decline phase - nutrient exhaustion, increased levels of toxic products
What are primary metabolites
List some examples
Substances produced by an organism as part of normal growth
Examples: amino acids, proteins, enzymes, Nucleic acids, ethanol, lactate
What are secondary metabolites
List some examples of
Substances produced by an organism that are not part of normal growth
(Only produced by a small number of organisms, usually produced to protect dwindling nutrients)
Examples: penicillin, streptomycin
What do all fermenters need
A starter population
How do industrial scale fermenters work
Starter population needed
Inlet for the addition of nutrients,
Electronic probes for
What conditions need to be monitored when culturing a microorganism
Nutrient addition
Temperature
Oxygen conc
pH
What are obligate aerobes
An organism that requires O2 to survive
What are facultative anerobes
An organism that can survive with or without the presence of O2
What are obligate anaerobes
An organism that can’t survive in the presence of O2
Describe continuous cultures
Nutrients added and products removed at regular intervals
Good for primary metabolite production
Describe batch cultures
Starter population of a microorganism
Specific quantity of nutrient solution
Grown for a fixed time
Products removed
Fermenter emptied
What type of metabolites are continuous and batch cultures good for
Continuous = primary
Batch = secondary
Define asepsis
The absence of unwanted micro-organisms
Define contaminant
Presence of unwanted micro-organisms
What are some aseptic techniques
Uv light
Autoclave - steam 121 degrees for 15 minutes
Loop, inoculate, spread
Flaming
What are large scale level aseptic techniques
Sterilisation of all equipment,
Filters on all inlets/ outlets,
Fermenters made of stainless steel - prevents sticking
Washing, disinfecting and steam cleaning
Why are enzymes used in industrial processes
Catalysts
Function at lower temperatures than inorganic catalysts - decrease cost
Specific - catalyses a specific reaction even if there is a mix of chemicals
What are isolated enzymes
Enzymes that are mixed in solution with the substrate - isolated from its original organism
Cell-free enzymes/ free enzymes
How do you isolate enzymes
- Culture the micro-organism in a fermenter
- Downstream processing - extract enzyme from fermentation mixture
What are the advantages and disadvantages of isolated/ free enzymes
Advantages - high rate of reaction
Disadvantages -
- downstream processing of products,
- enzymes not all recycled,
- proteases - break down the enzymes
Define immobilization of enzymes
Enzymes are attached to an insoluble support and are held separate from the reaction mixture
What 4 factors affect enzyme rate of reaction
Temperature
pH
Shape of active site
Access of substrate to active site
What are the advantages and disadvantages of immobilized enzymes
Advantages:
- immobilised enzymes can be reused (cheaper)
- product not mixed with enzymes (no separation needed)
- immobilised enzymes are more stable at high temps (thermostable) and extremes of pH
Disadvantages:
- Extra equipment - expensive
- immobilised enzymes are expensive
- immobilised enzymes have lower activity as they can’t mix freely with the substrate
What are the 3 methods of immobilising enzymes
- Encapsulated in jelly-like alignate beads, which act as a semi-permeable membrane
- Trapped in a silica gel matrix
- Covalently bonded to cellulose or collagen fibres
What are the examples of immobilised enzymes you need to know
Glucose isomerase - for conversion of glucose to fructose
Penicillin acyclase - for the formation of semi-synthetic penicillins (to which some penicillin-resistant organisms are not resistant)
Lactase - for hydrolysis of lactose to glucose and galactose
Aminoacylcase - for production of pure samples of L-amino acids
Glucoamylase - for conversion of dextrins to glucose
Nitrilase - conversion of acrylonitrile to acrylamide
What are the advantages and disadvantages of immobilising whole organisms
Advantages:
- no extraction - less expensive
- used when there’s a series of enzymes in reaction
- used when the enzyme is unstable/ inactive when removed from the cell
Disadvantages:
- some of the substrate is used by the cell
- expensive to maintain the microorganism - contamination
batch fermenters are used to produce penicillin
why is sterile air pumped into fermenter
provides oxygen for AEROBIC RESPIRATION
e.g. oxidative phosphorylation
explain why it is necessary to pump water into the jacket surrounding the culture in a batch fermenter
water used for cooling
maintains optimum temperature
as respiration produces heat
which would denature enzymes/ kill cells
state why pH is monitored and how its controlled in a batch fermenter
enzymes denature if pH is not optimum
add buffer in culture medium to control pH
give reasons for using microorganisms in the production of insulin and growth hormone
- avoid side effects/ immune response
- genetically engineer
- low risk of infection
- produce large amounts
- can be cultured anywhere in the world
define immobilised enzyme and describe how immobilisation can be achieved
immobilised enzyme = attached to an insoluble material/ kept separate from substrate
encapsulation in alginate beads
adsorption/ stuck onto collagen etc.
cross linkage/ covalent/ chemical bonding
gel entrapment
how should a plant cutting be taken for cloning
stem is cut between leaf and nodes - replanted and allowed to grow - sometimes with the use of plant hormones
what are some ways microorganisms are used in biotechnological processes
food: baking, brewing, yogurt, cheese
medicine: penicillin, insulin
environmental: removing pollution (bioremediation)
summarise the three steps of growing microorganisms
sterilisation: part of aseptic technique
inoculation: microorganism introduced to agar plate by streaking, seeding or spreading
incubation: placed in warm environment for 24-48 hours to grow
what are the phases in the standard growth curve for bacterial cultures
lag phase
exponential/ log phase
stationary phase
discuss the benefits of using immobilised enzymes for large scale-production of materials in biotechnology
- enzyme can be re-used so reduces cost
- product is pure/ uncontaminated
- reduced downstream processing costs
- works at higher temperatures
- works in changed pH
- reaction can be faster/ have a higher yield
what is meant by a primary metabolite
molecule made for cells to carry out normal functions/ survive
define recombinant DNA
DNA combined from two sources/ organisms
list three constituents of the culture medium for artificial growth of plants
water
amino acids
auxins
why is micropropagation more expensive than traditional methods
labour intensive
sterile conditions required
special equipment
trained staff
electricity/ power costs
quality of control
advantages of plant tissue culture
disease/ virus free
genetically identical/ clone
maintain favourable characteristics/ advantageous phenotypes
faster method
produces many plants
easily genetically manipulated
no external environmental influences
explain how egg cells are obtained for somatic cell nuclear transfer
animal superovulated
treated with hormone/ FSH
washed out of oviduct/ collected from ovary with syringe
suggest an advantage of immobilising whole cell rather than the enzyme
multiple enzymes within cells work simultaneously
