Using Microorganisms Flashcards
special types of bacteria called … can convert milk into …
the same bacteria can also turn milk into …
even the holes in Swiss cheese are made by …
blue cheese is blue because it it … types of fungi are added into the cheese to make the blue veins
lactobacillus yoghurt cheese bacteria mouldy
… is a type of fungus.
when it is added to … and oxygen it produces water and … in a process called aerobic …
this process is used to make …
yeast glucose carbon dioxide respiration bread
when yeast respires in the absence of …, it produces carbon dioxide and … (ethanol). This process is called … (anaerobic respiration) and is used to make alcoholic drinks such as wine and …
oxygen
alcohol
fermentation
beer
… is a thick sticky brown paste made from … extract and is a product of beer-making
marmite
yeast
in some countries like Brazil alcohol made from sugar can can be used instead of … in cars
petrol
certain bacteria can turn alcohol into an acid called acetic acid which is the scientific name for … Bacteria can turn all types of alcohol into vinegar including wine and code. vinegar can be used to make … in order to preserve food.
vinegar
pickles
a type of fungi is used to make … the fungi are grown in large chambers; collected and compressed together to form the blocks of … which is a health alternative to meat because it is high in … but low in … and as it is made from microbes, not animals, it is suitable for …
Quorn Quorn protein fat vegetarians
bacteria also carries out a process called … they break down dead plants, animals and animal waste into harmless products. this process can be used in … works where bacteria breaks down the sewage in order to turn it into clean water. bacteria also breaks down plant material to make … which is used in gardening to add … to the soil.
decay
sewage
compost
nutrients
some bacteria give out a gas called … when they carry out decay. this can be used as a fuel for … or making electricity. it is also the gas we have in our school …
methane
cooking
bunsen
burners
the fungus … produces a chemical called …. which acts as an … killing …
penicillium
penicillin
antibiotic
bacteria
finally, bacteria can be genetically modified (i.e. their genes altered), so that they make useful products, such as … this process is called …
insulin
genetic engineering
aerobic respiration yeast equation
glucose + oxygen –yeast–> carbon dioxide + water + energy
anaerobic respiration (fermentation)
glucose –yeast–> carbon dioxide + alcohol + some energy
how to measure respiration is occurring aerobically
one test tube with a bung have yeast and sugar solution
then a connecting test tube have limewater to detect CO2 levels
how to measure respiration is occurring anaerobically
one test tube with a bung have yeast and sugar solution with liquid paraffin on top with a connecting tube to the other test tube with limewater to detect CO2 levels
what does yeast use for fermentation of beer etc
ie barley grains during digestion of their starch to simple sugars, they then germinate producing an enzyme called maltase which breaks down the starch into maltose which the yeast can use for fermentation
most fungi are made from thread-like structures called … and have … made of chitin. they also have lots of the organelle called a … in their cytoplasm. the fungus used to make beer is single-celled and is called … this fungus uses a process called … respiration to convert a sugar called … into ethanol and a gas called …
hyphae cell walls mitochondria yeast anaerobic glucose carbon dioxide
describe an experiment you cold do to find out the effect of pH on the growth of yeast
Control - vary pH –> acid/alkali
Organisms involved - same species –> mass/number/concentration
Repetition - repeat each pH
Measurement 1 - mass/number/bubbles/carbon dioxide/alcohol
Measurement 2 - time period stated
Standard - same temp/volume of water/same nutrients/concentration of nutrients/oxygen –> don’t talk about light
how to make yoghurt with bacteria (type of respiration)
anaerobic respiration/lactic fermentation
bacteria making yogurt equation
lactose (milk sugar) –bacteria–> lactic acid + some energy
lactic acid makes milk go …
the low … causes milk proteins to … and … is formed
the low … also prevents … bacteria from growing
sour pH curd clot pH harmful
steps of making yogurt
1) milk is pasteurised at 85-95 degrees (to kill off bacteria)
2) milk is homogenised (to make sure fat is mixed in)
3) milk is cooled and inoculated with Lactobacillus (so that Lactobacillus’ enzymes does not denature)
4) milk is incubated for several hours (optimum temperature for enzymes so they respire as much as possible)
5) flavourings and fruit are added
why add nutrients and glucose to a fermenter
healthy growth and respiration
why and how is pH controlled in a fermenter
as pH will affect wroth of microbes you need to stop enzyme damage, add acid/alkali
why control temperature in a fermenter
too hot –> enzymes denature
too cold –> work less effectively
why stir the contents of the fermenter
keeps a consistent environment for pH, temp and sensors wouldn’t work as well, microbes reach all the nutrients
how big are normal fermenters
can hold up to 200000 litres
examples of need for fermenters
penicillin, insulin, quorn
how can contamination of the fermenter be avoided
sterilise fermenter, anything going in should be sterilised (even the air), be careful which microbes are added
what is the importance of the water jacket around fermenters
to stop enzymes denaturing or working less efficiently, to maintain a constant temperature
why is steam used to clean the fermenters
no chemical contamination, but completely cleans and sterilises
