Unit 6^ Microorganisms + Genetic Modification Flashcards
What is meant by the term ‘fermentation’
Using the respiration of microorganisms to produce useful products
What is meant by the term ‘aseptic’
Aseptic means complete absence of other organisms
What type of bacteria ferment milk to produce yoghurt
LACTOBACILLUS bacteria
What is a disaccharide
A sugar made up of 2 monosaccharides (e.g. of glucose + fructose)
What is meant by the term ‘transgenic organism’
An organism that has been engineered w a gene from another species
Why can genes from one organism work in another organism?
All organisms use the same genetic code = UNIVERSAL CODE
What is meant by the term ‘recombinant DNA’
When a gene from another organism is cut out + inserted into another this new DNA is recombinant dna 🧬
Give a real life example of a vector used in genetically modifying plants
AGROBACTERIUM = a vector which is regularly used to inserts plasmids into bacterium cells
What is a vector
Structures such as plasmids + vectors which can be used to take up pieces of DNA + insert this recombinant DNA into other cells
What is meant by the term ‘transgenic’
Transgenic, is the transfer of genetic material from one species to another species
Describe how genetically modified bacteria can be used to produce insulin
A human cell which contains the gene that codes for insulin (or the gene we want) can be cut using a RESTRICTION ENZYME.
This same restriction enzyme should then be used to cut the plasmid DNA out of a bacterial cell, by cutting with the same restriction enzyme— it generates complimentary shapes
The enzyme LIGASE then covalently bonds the sticky ends of the 2 fragments of DNA together
This produces RECOMBINANT DNA which is inserted into the bacteria 🧫 Which reproduces itself
Describe the role of yeast in the production of bread
🥖Bread dough is made of yeast + flour + water + lil sugar
🥐Left to rise in warm place
🍞Enzymes break down carbohydrates in flour into sugar
🥖Yeast uses these sugars in aerobic respiration = producing co2 + water
🥐When o2 runs out the yeast switches to ANAEROBIC respiration to produce co2 + ethanol
🍞Co2 bubbles trapped in dough expand in oven
🥨Baking kills the yeast + the evaporates ethanol
Investigate the role of anaerobic respiration by yeast in different conditions (+ how does one improve accuracy of experiment)
1) mix together yeast, sugar + distilled water
2) attach a bung w a tube leading to a second test tube of water
3) seal both tubes to stop o2 getting in
4) place yeast mix in a water bath at a set temp
5) leave tube to warm up a bit + count how many bubbles are produced per min
6) repeat at different temperatures of water bath
7) calculate rate of co2 produced (no. Of bubbles/time taken) = dis is also respiration rate
(To improve accuracy use a gas syringe)
What different factors affect rate of anaerobic respiration
- temperature
- concentration of sugar
- different types of sugar (glucose, sucrose, maltose, fructose)
Describe the role of lactobacillus in the production of yogurt
🥥equipment sterilised to kill off unwanted microorganisms
🥥 milk is pasteurised at 85-95*C for 15-30 min
🥥milk is homogenised (shaken to disperse fat globules)
🥥milk is then cooled to 40-45*C + INOCULATED w a culture of lactobacillus bacteria
🥥the mixture is then INCUBATED at this optimum temperature in a fermenter
🦠the LACTOBACILLUS bacteria ferment the lactose (sugar in milk) into LACTIC ACID
🦠this lactic acid makes conditions acidic which makes the proteins in the milk denature = YOGURT
🥥the thickens yogurt is cooled to 5*C + flavourings/fruit may be added
