UNIT 21 Biotechnology and genetic modification Flashcards
why are bacteria useful in biotechnology
and genetic modification [2]
their rapid reproduction rate
-their ability to make complex molecules; same genetic code so can produce same proteins.
📌 few ethical concerns over their manipulation and growth
📌 the presence of plasmids [ideal way of transferring DNA from one cell to another during genetic manipulation; easy to remove & manipulate]
Suggest how the problem of antibiotic resistance can be limited. [4]
prescribe/ use, antibiotics less often ;
not for, viral/ fungal, infections ;
make sure people complete the course of antibiotics /AW ;
develop new antibiotics ;
do not use the same antibiotics for too long/rotate antibiotics /AW ;
use combinations of antibiotics ;
genetic modification [3]
Changing the genetic material
of an organism
by removing, changing or inserting individual genes from another organism
process of genetic modification using
bacterial production of a human protein as an example [6]
-Identify gene of interest in original organism.
-genome of original organism will likely need to be sequenced to identify its location.
📌 isolation of the DNA making up a human gene using restriction enzymes, forming sticky ends [shortsectionofunpairedbases]
📌 cutting of bacterial plasmid DNA with the same restriction enzymes, forming complementary sticky ends ; [makes sure that no other DNA can bind in to the plasmid]
📌 insertion of human DNA into bacterial
plasmid DNA using DNA ligase to form a
recombinant plasmid by joining plasmid & isolated gene.
📌 insertion of recombinant plasmids into
bacteria [plasmid is inserted into the bacterial cell => called a “transformed” bacterial cell, reproduced in fermenter]
📌 multiplication of bacteria containing
recombinant plasmids [bacteria replicate => copy plasmid => all bacteria in fermenter have gene & produce protein]
📌 expression in bacteria of the human gene to make the human protein
gene & plasmid joined tgt by DNA ligase enzyme => if two pieces of dna have matching…
if 2 pieces of DNA have matching sticky ends (bc they’ve been cut by same restriction enzyme),
DNA ligase links them to form single unbroken molecule of DNA
examples of genetic modification [4]
📌 insertion of human genes into bacteria to produce human proteins; gene for human insulin.
📌 the insertion of genes into crop plants to confer resistance to herbicides; only kill weeds, not plants.
📌 the insertion of genes into crop plants to confer resistance to insect pests; modified to contain a gene from a bacterium produces a poison to kill insects
📌 the insertion of genes into crop plants to improve nutritional qualities; produce additional vitamins, prevent deficiency diseases (golden rice - vitamin A)
role of anaerobic respiration in yeast
during the production of ethanol for biofuels
-yeast uses glucose as food source
respires anaerobically, c2h5oh, BIOFUEL, & co2 produced. energy released.
-plant material (substrate) for producing c2h5oh as source of c6h12o6, chopped, mixed w/ yeast, respires….
-liquid separated from solid, h2o removed, leaving concentrated solution of ethanol.
-adv: using waste parts (stalks/outer leaves), disadv: less land available for necessary crops.
role of anaerobic respiration in yeast
during bread-making
-yeast mixed w/ flour & water
C6H12O6 -> 2C2H5OH + 2CO2.
co2 produced by yeast during respiration makes bread dough rise
use of pectinase in fruit juice
production
-adding enzyme pectinase to chopped up fruit => more juice released
-pectinase works by breaking down pectin found inside plant cell walls
-pectin broken down => cell walls break more easily, more juice
-pectinase helps produce clearer juice as pectin can make juice cloudy; broken into smaller molecules.
use of biological washing powders that contain enzymes
-stains = organic molecules.
soap => lot of time, effort, high temp.
adv: quick, work lower temp, delicate fabrics
biological washing powders ADV [3]
📌 quickly breaking down large, insoluble molecules (fats, proteins) into smaller, soluble ones to DISSOLVE in washing water.
📌 effective at lower temp; less energy & money used
📌 delicate fabrics not suitable for high temp wash
use of lactase to produce lactose-free
milk
what is lactose? lactase? symptoms
-lactose = sugar found in milk.
-lactase, enzyme that breaks down lactose. ppl lose ability to produce lactase as they should get older
📌 symptoms of lactose intolerance: nausea, flatulence, diarrhoea
how milk is made lactose free
📌 adding enzyme lactase to milk
leaving to stand, allow enzyme to break down lactose.
how fermenters can be used for the large-scale production of useful products by bacteria and fungi
📌 PENICILLIN [first antibiotic; produced by fungus]
how? fermenter? in/out? adv?
-bacteria killed by penicillium mould (produces a chemical, prevents infection)
INDUSTRIAL FERMENTERS (containers to grow bacteria & fungi in large amounts):
-steam, nutrients, cooling water, air in
-cooling water out, product.
-adv of fermenter: conditions can be carefully controlled, produce large, right type of microorganism
CONDITION, why & how it’s CONTROLLED
- aseptic precautions
fermenter cleaned by steam to kill microorganisms. prevent chemical contamination. ensures only desired microorganism can grow
- nutrients
needed for use in respiration
to release energy for growth & reproduction of microorganisms
- optimum temp
-temp monitored using probes, maintained using water jacket.
-ensures optimum environment for enzymes to increase enzyme activity & prevent denaturation
- optimum pH
-pH monitored using a probe
-check it’s optimum value for microorganism grown
-adjusted using acids & alkalis
- oxygenation
-oxygen required for aerobic respiration to take place
- agitation
-stirring paddles used to ensure temp, pH, nutrients & oxygen distributed evenly throughout fermenter
- waste
contents filtered to remove waste created by microorganisms
mycoprotein (vegetarian protein-rich food) - creating food from fungus, Fusarium
-optimum pH, temp, grown in aerobic conditions, glucose as food source to allow fungus to respire
-fungal biomass harvested, purified to produce mycoprotein
production of insulin
-genetic modification. dna of organism now contains dna from another organism = recombinant DNA
-gene for human insulin has been inserted into bacteria, then produce HUMAN INSULIN; collected, purified for medical use to treat those with diabetes.
advantages and disadvantages of
genetically modifying crops (soya, maize, rice)
📌1st adv - envir, cheap, time
-reduced use of chemicals (herbicides & pesticides) - better for environment, cheaper, less time-consuming for farmers
