6.2.1 cloning and biotechnology Flashcards
what is a clone
genetically identical organism or cell
examples of natural cloning in plants
- runners - strawberry
- rhizomes - ginger
- tubers - potato
- bulbs - onions
how to take a cutting
- cut plant between nodes - scalpel - 45 degrees
- dip into rooting powder (auxin)
- put in moist soil
- leave in humid conditions (cover with plastic bag)
- wait until roots develop
why do you have to keep plants in humid conditions when taking cuttings
reduce transpiration rate
process of micropropogation
- sterile scalpel/forceps - cut leaf into small pieces
- transfer explant to sterile nutrient agar
- divides into callus
- using root and shoot stimulating hormones
- develops into plantlets
- transfer to soil for growth
pros of micropropogation
- fast prod. of genetically identical plants
- can clone to make rare or endangered species
- make seedless plants
cons of microporopagation
- expensive
- no genetic variation - vulnerable to disease
- contamination
- labour intensive
example of natural cloning in animals
identical twins
- zygote splits
process of SCNT
somatic cell nuclear transfer
- take a somatic cell from sheep (udder)
- remove nucleus from somatic cell
- enucleation of egg donor’s egg
- somatic cell nucleus inserted into enucleated egg
- electric shock - to fuse + stimulate division
- implant to surrogate mother - clone produced
pros of SCNT
- high yield livestock
- save endangered species
- for medicine
cons of SCNT
- expensive
- health issues in clones
- reduces genetic diversity
enucleation definition
removing nucleus from cell
what is therapeutic cloning
- cloning of human cells for medical purposes
- growing tissues or organs for transplant
why use microorganisms in biotechnology?
- short life cycles - fast reproduction
- less energy and little labour
- food production
- medicine - antibiotics
- treatment of waste
examples of biotechnological uses
- penicillium mold - produces penicillin
- yeast - makes bread and beer
- lactic acid + bacteria - make yogurt and cheese
- fungi - mycoprotein - quorn
advantages of microorganisms in food production
- high protein content esp in fungi
- less land required - reduces impact to the land
- grow in controlled environments so climate change has no effect
disadvantage of microorganism in food
- people might find it unappetising because of taste and texture
- contamination of cultures mean it becomes toxic
how to use aseptic techniques
- disinfect surfaces using alcohol based disifectants
- pass inoculating loops through flame to sterilize
- sterile equipment - sterile agar plates/broth
- keep petri dish lids closed
describe batch fermentation
- closed system - nutrients added at start
- fermentation stops when nutrients are depleted
- used for penicillin and enzymes
describe continuous fermentation
- open system - nutrients continuously added
- allow constant productions
- used for yeast in brewing
factors that affect yield
- pH
- temp
- oxygen levels
- nutrient supply
describe what happens in the growth curve
- lag phase - cells are adjusting to environment - slow growth
- log phase - exponential - rapid cell division
- stationary phase - growth=death rate
- death phase - nutrients run out, waste accumulates - death
microbial growth formula
N = N0 x 2^n
N = final population size
N0 = initial population size
n= number of generations
aerobic Vs anaerobic fermentation
aerobic
- more ATP
- higher yield of products
- e.g penicillin
anaerobic
- less ATP
- used in beer - yeast respire anaerobically
what are immbolised enzymes
enzymes that is fixed in a material so it does not mix freely with the reaction mixture
why use immobolised enzymes
- don’t denature easily
- reusable
- can be separated easier - no contamination with the final product
describe and evaluate using absorption
- enzymes attach to a surface e.g clay with ionic/hydrophobic interactions
Pro
- cheap, easy
Cons
- enzymes detach easily
describe and evaluate covalent bonding
- enzymes are covalently bonded to a surface e.g clay
Pros
- strong attachment = no enzyme leakage
Cons
can reduce enzyme activity if binding site is affected
describe and evaluate entrapment
- enzymes trapped in a gel e.g silica
Pros
- protects enzymes
Cons
- substrates can diffuse out = slower ROR
describe and evaluate membrane encapsulation
- enzymes are enclosed in a semi-permeable membrane
Pros
- seperates enzyme from mixture
Cons
- diffusion can limit speed or reaction
industrial use of immobolised enzymes
- HFCS - high fructose corn syrup
- lactose free dairy
- starch breakdown
disadvantages of immobolised enzymes
- setting up immobolised enzymes is expensive
- slower beacause they are less active than free enzymes
