Cloning and Biotechnology (Population Growth in a Closed Culture (Lag…
Cloning and Biotechnology
Tissue culture & Micropropagation:
"Growing large numbers of new plants from meristem tissue taken from a sample plant"
Cells taken from meristem tissue and sterilised with alcohol - explants.
The explants are places in nutrient agar causing them to proliferate to from big balls of cells called callus.
The callus are treated with shoot and root growth stimulating hormones.
Plants are planted in compost.
Stem cut between two leaf joints.
Cut end placed in moist soil.
New roots grow from tissues in the stem.
Same environment suitable for parent and offspring.
Only requires one parent.
No genetic diversity.
Natural selection impossible.
Entire population vulnerable to environmental changes.
"The process of reproduction through vegetative parts of the plant, rather than through specalised reproductive organs"
Plant is damaged and root sucker appears on plant.
Root suckers grow from meristem tissue which contain stem cells.
Offspring are genetically identical.
Zygote devides early in development.
Each cell is genetically identical.
D.pulex & A.pisum
Species that reproduce asexually.
Zygote is created by IVF.
Zygote divides by mitosis to form a small ball.
Cells separated and continue to divide.
Each small mass of cells placed in uterus of a surrogate mother.
Somatic cell nuclear transfer:
Egg cell obtained and nucleus removed by enucleation.
A nucleus from a normal body cell is fused with the empty egg by electro-fusion.
The electric shock triggers the egg to start dividing.
The embryo is placed in the uterus of a surrogate mother.
High-value animals can be cloned.
Endangered animals can be preserved.
Long term health of animals unclear.
Lack of genetic variation.
Animal welfare may be forgotten.
"The use of living organisms or parts of living organisms in industrial processes"
Metabolites can be harvested.
Can be genetically engineered to produce specific products.
Not dependent on climate.
Bacteria converts lactose to lactic acid in milk. This acidity then denatures the milk protein causing it to coagulate.
Bacteria converts lactose to lactic acid.
The enzyme rennin is added which coagulates the milk in the presence of calcium ions.
The resulting solid (curd) is removed from the liquid and pressed into moulds.
Flour, water, salt and yeast is mixed together to produce dough
The dough is left in a warm place while the yeast respires anaerobically.
The risen dough is baked.
Anaerobic respiration by yeast.
Production easily regulated.
Small area taken up.
Protein contains no fat.
Independent of seasons.
Risk of infection.
Protein need to be purified.
Protein needs to be isolated from growth substrate.
Fungi placed in a fermenter and culture then filtered to remove cells.
Antibiotic precipitated as crystals by the addition of potassium.
Antibiotic prepared in tablet form.
Insulin produced from genetically engineered bacteria.
Waste water treatment.
Aseptic Culture Technique
Disinfect working area
Heat nearby air with a bunsen burner.
Avoid removing lid of petri dish directly..
Pass metal or glassware through a flame.
Medium heated in an autoclave for 15 mins at 121°C to kill all living organisms.
Lid kept on petri dish to prevent unwanted organisms entering.
"The introduction of microorganisms into the sterile medium"
Wire look with microorganism on it dragged across agar.
Pipette used to drop liquid medium on agar.
Glass spreader used to spread the drop across the agar.
Petri dish placed in warm environment.
Place upside down to prevent condensation falling on agar.
Don't open petri dish.
Observe culture growth after 24/48 hours.
Wash petri dish after use.
Manipulating the Growth Conditions in Fermentation
Thermometer monitors temp.
Water jacket lowers temp caused by respiration.
Inlet for addition of nutrients.
Air inlet delivers oxygen.
High pressure steam sterilizes environment.
Probe measures pH levels.
Alkali can be added if pH rises.
Concentration of products:
Outlet tap to remove fermenter.
Mixing bladed stir mixture.
Pressure vents prevent gas build up.
Products continually removed.
Maintain culture in the log phase.
Difficult to set up.
Maintain culture in stationary phase.
Easy to set up.
Produce secondary metabolites.
Population Growth in a Closed Culture
Cells increase in size.
No cell division.
Ensures a stable environment.
Population remains constant.
High metabolic activity & reproduction.
Enzymes available to survive.
Nutrient levels decrease.
Toxic metabolites build up.
Organisms die at the rate they are produced.
Increased levels of toxic metabolites.
Organisms die and the population decreases.
Produced by organism as part of normal growth.
e.g. Amino acids, lipids ect.
Produced during log phase.
Substances produced that are not part of normal growth.
Produced during stationary phase.
"Repeated dilutions of a solution in order to reduce its concentration"
Allow us to reduce the number of organisms to study them better.
"An enzyme that is fixed and unable to move freely throughout a solution"
Enzyme doesn't mix with product.
Enzyme can be reused.
No cells requiring nutrients.
Enzymes surrounded by the immobilising matrix which protects them from extreme conditions.
Immobilised enzymes less active so process is slower.
Methods of immobilising.
Enzymes bound to a surface by hydrophobic interactions and ionic bonds.
Active site may be slightly distorted.
The bonds are week and enzymes can break loose.
Enzymes are trapped in a matrix that prevents them from moving.
Enzymes are fully active.
Substrates and products must diffuse through matrix.
Semi-permeable membrane around enzymes.
Substrate small enough to pass through membrane.
Limits rate of reaction.
Converts glucose to fructose.
Forms semi-synthetic penicillins.
Hydrolyses lactose glucose and glactose.
Produces pure samples of L-amino acids.
Converts dextrins to glucose.