Unit 21 - Biotechnology and genetic modification Flashcards
Biotechnology
The exploitation of biological processes by humans for industrial and other purposes
Genetic engineering / Genetic modification (GM)
Changing the genetic material of an organism by removing, changing or inserting individual genes
How humans use bacteria
- Food production
- Breaking down sewage
- Production of useful chemicals
- Production of antibiotics and food supplements
- Making hormones e.g. insulin
- Conversion of wastes into fuel
- Making transgenic plants
- Cleaning oil spills
Reasons why bacteria is useful
- They can reproduce rapidly
- They can make complex compounds e.g. vitamin B12 & insulin
Role of plasmids in genetic modification
A gene for a protein is inserted in the plasmid and is then transferred to the genetic material of a bacterial cell which will express the gene and make the protein
Yeast
A microscopic single-celled fungus
Yeast anaerobic respiration equation / fermentation
C6H12O6 –> 2C3H5OH + 2CO2
Alcohol produced by yeast
ethanol
Ways to make ethanol
- Ethene reacting with steam at high temperatures
- Cellulose digested by enzymes mixed with yeast and water in a warm oxygen-free atmosphere
Use of ethanol as a fuel
Can be used directly or mixed with petrol to make biofuel
Use of yeast in bread
When oxygen is used anaerobic respiration happens and carbon dioxide causes the bread to rise whilst ethanol boils due to the oven
Common industries that use enzymes and how
- Production of fruit juice - pectinate used to break down pectin (protein that holds cell walls together) to allow juice to be extracted easily
- Biological washing powders - enzymes are in washing powders to break down the substances in fabric stains
Reason for lactose intolerance
A lack of lactase that is produced in the wall of intestines and breaks lactose into glucose and galactose
Making lactose-free milk
- Lactase is mixed with alginate gel
- Alginate beads are made that immobilize the enzyme
- Enzyme can then be used repeatedly since it can’t be washed away with the product
- Milk is passed through a mesh with the enzyme for several cycles until no more lactose is detected
Role of a fermenter
Designed to optimize the growth of a microorganism such as bacteria - usually a stainless steel structure with a water jacket
Features of a fermenter
- Stirrer - keeps everything evenly distributed
- Nutrients are microorganisms are put in
- Sterile air supply
- Probes to measure temperature, pH & oxygen levels
- Water-cooled jacket - keep mixture at optimum temperature
- Product comes out
Production of penicillin
1 - penicillium mold naturally produces the antibiotic penicillin
2 - Naturally produced in a fermenter with a solution containing sucrose and penicillium
Substances that are produced by fermenters
- Penicillin
- Mycoproteins
- Insulin
Genetically modified organisms
- Humans - proteins can be inserted to treat people e.g. insulin with type 1 diabetes
- Herbicide resistant plants - genes can be inserted to make crops herbicide resistant
- Insect resistant plants - Genes can be inserted into crops to give them resistance to pests e.g. bt corn
- Food with improved nutritional qualities - vitamin and amino acid contents can be increased
Steps of genetic modification
- Isolating the section of DNA that makes up the required human gene
- Cutting the DNA of a bacterial plasmid
- Inserting the human DNA into the plasmid DNA
- Inserting the plasmid into bacteria
- Allowing the genetically modified bacteria to express the gene and make the human protein
Restriction enzymes
Cut DNA at particular places
Sticky ends
Ends of single-stranded DNA cut by restriction enzymes
Recombinant plasmid
Name for the plasmid that has been changed by the insertion of the gene
Ligase enzymes
Join sticky ends together to make a complete length of double-stranded DNA
