6.2 Cloning and biotechnology Flashcards
clone definition
genetically identical to their one parent
formed by asexual reproduction
cloning in eukaryotes
mitosis
cloning in prokaryotes
binary fission
examples of natural clones
animals: identical twins
plants: corms, leaves, suckers, bulbs, rhizomes, runners, tubers
cloning in plants / asexual reproduction
vegetative propagation
advantages of clones
quick (increased chance of population survival and genetic material being passed on, quicker evolution)
all offspring have genes to survive in environment (increased chance of survival)
possible when sexual reproduction fails/isnt possible (maintain population numbers)
disadvantages of clones in general
overcrowding (increased competition)
no genetic variation (susceptible to disease / sudden changes in environmental factors = population may die)
vegetative propagation definition
production of structures in an organism that can grow into new organisms, genetically identical to the parent (thus being clones)
how natural cloning in plants is possible
many parts of plants contain meristematic, undifferentiated tissue
can divide and differentiate to form a range of different cell types
runners, rhizomes and suckers features
plants grow horizontal stems
underground = rhizomes
on surface of ground = runners/stolens
Suckers = stems that grow from roots of plants
bulb features
underground stem grows into series of fleshy leaf bases
apical bulbs grows from it which grow into separate plants
corms features
underground stem with scaly leaves and buds
remain in ground over winter
in spring, buds grow to produce one or more new plants
solid
leaves in cloning features
clones grow on leaf margins
drop off leaf and take root
tubers features
underground stem
will grow into one or more plants
can produce many new tubers (potatoes) later that year
cloning in animals
identical twins
when zygote divides as normal but 2 daughter cells split to become separate cells
develop as new individuals
plant cuttings method
stem is cut at a node (2 leaf joints)
remove bark if present to avoid formation of a callus
add rooting powder depending on plant species (some take root less easily)
cut end of stem is buried into soil
new roots begin to grow into soil
this process is also possible from root, leaf and scion cuttings
grafting method
place portion of one plant (bud/stem/scion) into stock of another plant (root/branch/stem)
forms a graft union and both will continue to grow
union is wrapped and waxed to stabilise it
micropropagation method
tissue from apical buds taken as it is meristematic and still undergoing mitosis (explant)
surface cleaned using dilute bleach/alcohol to ensure aseptic conditions (no bacteria will then compete with plant tissue)
explant placed onto nutrient medium to encourage mitosis
forms a callus (mass of undifferentiated cells)
callus subdivided and placed in new nutrient medium to encourage differentiation of tissue
contains auxins, cytokinins, magnesium, nitrates, sucrose
callus cells growth into plantlets and can then be placed into sterile soil
auxins in micropropagation
stimulate formation of root hairs
cytokinins in micropropagation
stimulate shoot growth
magnesium in micropropagation
helps plant make chlorophyll
nitrates in micropropagation
needed in protein synthesis
sucrose in micropropagation
converted to glucose for respiration
advantages of clones instead of seeds
maintains favourable characteristics of mother plant quicker to produce, more produced more likely to survive in lab conditions disease-free easily genetically manipulated can be used for cloning infertile plants easy to transport/store
disadvantages of clones instead of seeds
geneticaly identical (all susceptible to some diseases) = loss in genetic diversity farmers have to buy plants from suppliers = high cost labour intensive patented property
embryo twinning method
zygote created by IVF
allowed to divide to form small ball of cells
cells separated and continue to divide
each of these cells placed into surrogate mother
use of embryo twinning
cloning “elite” farm animals
scientific research
cloning animals by nuclear transfer method
egg cell enucleated
adult somatic cell diploid nucleus from a different animal removed and injected into enucleated egg cell (or adult cell fused with enucleated egg cell)
cell given a small electric shock to stimulate mitosis
cells grows into an embryo in vitro
embryo can be split into several embryos to produce artificial identical twins
embryo(s) implanted into surrogate mother(s)
collecting eggs for cloning
treated with hormones with FSH
superovulation occurs
collect eggs from ovaries
why clone is not entirely genetically identical to nucleus donor
mitochondrial DNA found in cytoplasm
only DNA in nucleus of cell donor is taken
therapeutic cloning uses
new tissues and organs can be grown and replaced in patients where they are damaged e.g. skin grafts, beta cells producing insulin, spinal cord damage
how surrogates could be prepared for implantation of embryo
hormone treatments
prepare uterus for implantation by causing lining to thicken so increased blood supply for the placenta
advantages of animal cloning
scientific research elite farm animal production produce desirable characteristics reduce possibilities of disease species preservation
disadv of animal cloning
lack of genetic diversity
ethical reasons
biotechnology definition
industrial use of living organisms to produce food, drugs or other products
4 main areas of biotechnology
food
drugs
enzymes
other products
major advantages of microorganisms in biotech
cheap + easy to grow
genetically modified easily (less ethical issues)
high temp. not required (saves fuel costs)
normal atmospheric pressure can be used (safer)
not dependent on climate (can be done anywhere)
products released (easy to harvest)
short life cycle (can reproduce very quickly)
purer products produced
waste products from other processes can be reused (occasionally requires pre-treating)
how yoghurt is made
milk undergoes fermentation
Lactobacillus bulgaricus and Streptococcus thermophillus convert lactose to lactic acid
acidity denatures milk protein, causing it to coagulate
bacteria partially digests milk (easy to digest)
other bacteria may be added as probiotics
probiotics in yoghurt
bacteria that may benefit human health by improving digestion of lactose
aid in gastrointestinal function
stimulate immune system
how cheese is made
pre-treated with Lactobacillus bacteria to produce lactic acid from lactose
mixed with rennet
enzyme rennin (chymosin) in rennet coagulates casein (milk protein) in presence of Ca2+ to form curd
curd separated from whey (liquid part) by cutting, stirring and heating
bacteria continues to grow as curd cut into moulds
flavour determined by later ripening and maturing processes
where rennin is found
stomachs of young mammals
how rennin coagulates casein
kappa-casein (keeps casein in solution) is broken down
casein is now insoluble
casein precipitated by Ca2+
binds molecule together to form curd
method and microbes in baking bread
mix and knead ingredients together to form dough
prove dough in warm environment (allows yeast (Saccharomyces cerevisiae) to respire anaerobically)
produces CO2 bubbles, causes dough to rise
alcohol produced in proofing is evaporated off in cooking
microbes in alcoholic beverage production
wine: yeast from grapes’ skin produces alcohol when anaerobically respire from natural sugars
beer: yeast (Saccharomyces cerevisae) ferments sugar from barley
hops give bitter taste
penicillin production
Penicillium chrysogenum
made in batch culture (secondary metabolite so only produced when pop. has reached certain size)
penicillin made after 6-8 days in fermenter
precipitated out of mixture by potassium compounds, purified and put into tablets
insulin production method
made in continuous culture (primary metabolite
bacteria genetically modified and grown in fermenter
continually harvested, purified and bottled as medicine
bioremediation method
microbes clean polluted soil and water
use toxic pollutants to respire and convert them to less harmful substances
Pseudomonas
SCP stands for
single-cell protein
mycoprotein
most frequently used microorganism for SCP production
Fusarium venenatum
batch fermentation features
fixed quantity of nutrients at start (no more added)
at end, process removed and tank emptied (process started again)
growth slower
easy to set up and maintain
contamination = loss of just one batch
less efficient
produces secondary metabolites after exponential phase during stationary phase (nutrients deplete)
continuous fermentation features
nutrients and products added and removed from culture continuously
growth faster
quite difficult to set up and maintain
contamination = loss of more product
more efficient
produces primary metabolites during exponential phase (nutrients dont deplete and cultures stays in exponential phase)
standard growth curve phases
lag phase (bacteria start to grow) exponential phase (population grows exponentially) stationary phase (population growth stops as death rate = reproduction rate) death phase (bacteria die faster than they multipy)
metabolites definition
products of metabolic reactions
primary metabolites features
produced during exponential growth phase
essential for normal cell growth/reproduction
matches growth in population
secondary metabolites features
produced during stationary phase
not essential for normal cell growth/reproduction
doesnt match growth in population
microorganism population growth formula
N = No x 2^n No = number of cells in population at start N = number of cells in population n = number of generations that have occured
importance of asepsis when manipulating microbes
reduces competition
prevents a reduced yield
prevents a spoilt product (toxic chemicals produced by unwanted microbes)
asepsis vs sterile
asepsis = no microorganisms at all sterile = no harmful (pathogenic) microorganisms
types of growth medium
broth (liquid)
agar (jelly like substance in a Petri dish)
2 main nutrient requirements for growing microorganisms
carbon-containing compounds for respiration
nitrogen-containing compounds for protein synthesis
how to avoid contamination when transferring microorganisms from broth to agar
wash hands
disinfect surfaces
heat the air so microorganisms don’t settle
flame the opening to any microorganism when containing vessel before and after
flame equipment
limit air exposure e.g. when Petri dish lid is removed
sterilisation for growing microorganisms method
growth medium sterilised in autoclave heated to 121°C for 15 minutes and poured into sterile Petri dish
sterilise equipment through heating
inoculation methods
streaking: wire of inoculating loop used to drop liquid medium onto agar, loop is used to drag medium across surface of agar
spreading: sterile glass spreader (or cotton bud moistened with distilled water) can move liquid medium across the whole surface of agar
seeding: sterile pipette used to transfer a drop of liquid medium to agar surface or before it is poured for setting
incubation details
stored upside down warm environment examined after 24-36 hours do not open each colony is from a single bacteria sterilised after use and before disposal
inoculation steps
loop flamed
cap removed from sterile broth
unheated loop inserted into tube of sterile broth
loop removed from broth and tube mouth is flamed
tube enclosure returned to tube
immobilised enzyme definition
enzymes attached to an insoluble material in order to keep them separate from the reaction mixture
immobilised enzyme advs. in general
more cost-effective as enzyme remains separate from products and can be reused
how to immobilised enzymes method
entrapment: trapped in alginate beads or cellulose mesh
adsorption: stuck onto collagen/clay/resin/porous glass (covalent bonding to clay)
membrane separation: partially permeable membrane
advs of immobilised enzymes in large scale production
product is uncontaminated by enzyme therefore no downstream processing needed (cheaper)
not lost during process and therefore reuseable (cheaper)
matrix protects the enzyme so enzyme works at higher temp. so reactions can be faster as done at higher temp.
matrix protects enzyme so enzyme works in changed pHs
suitable for continuous culture (long shelf-life)
disadv of immobilised enzymes in large scale
immobilisation difficult/expensive
can be less efficient as substrate has to get through beads so don’t form ESCs as readily
aminoacylase function
produces pure samples on L-amino acids by removing acyl group from the nitrogen of an N-acyl-amino acid
glucoamylase function
during hydrolysis of starch, short polymers of glucose are made (dextrins) which can then be further hydrolysed into glucose
glucose isomerase function
converts glucose to fructose to make high fructose corn syrup
nitrile hydratase definition
converts nitriles to amides (some used to make plastics)
lactase function
converts lactose to glucose and galactose by hydrolysis to make lactose-free milk
penicillin acylase/amidase function
creates semi-synthetic penicillin
