B6 - Useful microorganisms Flashcards
What is bacteria used to make?
- yoghurt when milk is turned sour by bacteria
- silage when grass is fermented
- cheese when milk uses bacteria to help it ripen
- vinegar when bacteria make acids from alcohol
- compost when bacteria breaks down dead plant material
How do we know yeast is alive?
It needs food and water to grow.
When yeast breaks down sugar what does it turn it in to?
Alcohol and carbon dioxide.
What is fermentation?
Fermentation is turning sugar into alcohol.
Why is fermentation a special kind of respiration?
It does not require oxygen.
What are the five stages in the production of yogurt?
1) milk is pasteurised
2) milk is cooled down
3) a bacterial culture is added to the milk
4) samples are taken to find out when the yoghurt is ready
5) flavors and colors are added
Why is fermentation anaerobic respiration?
It doesn’t use oxygen:
glucose = ethanol + carbon dioxide
What is the bacteria called that is used to make yoghurt?
The bacteria is called Lactobacillus.
What does Lactobacillus do?
Lactobacillus converts the lactose into lactic acid.
What is the chemical symbol for ethanol?
The chemical symbol for ethanol is C2H5OH.
Write down the balanced symbol equation for fermentation.
C6H12O6 = 2C2H5OH + 2CO2
Why does fermentation require no oxygen?
To ensure that yeast produces alcohol rather than carbon dioxide and water.
Why do spirits have a higher concentration of oxygen?
Some of the water has been removed.
Name one drink made by the process of fermentation.
Beer
OR
Wine
What is beer made from?
Beer is made from barley grains.
