Microbes and Food production Flashcards
What is respiration?
It is a chemical reaction that occurs in every cell in our body. (It is NOT the same as breathing)
What is aerobic respiration?
Glucose + Oxygen –> carbon dioxide + water (+ energy)
What is in yeast?
Glucose –> Ethanol + Carbon dioxide ( + a little energy)
What is ethanol?
It is Alcohol.
What is an animal without oxygen in anaerobic respiration?
Glucose –> Lactic acid (a little bit of energy is released)
What does milk contain?
It contains sugar lactose.
What does the milk become?
It becomes more acidic and causes proteins to coagulate and thicken the mixture.
Facts about Yeast.
- Yeast uses sugar to respire.
- Yeast is a single celled fungus.
- Yeast uses the energy from respiration to move and reproduce.
- Sugar makes bread rise because the sugar in the dough respires and this produces carbon dioxide.
What is brewing?
It is a specialised type of fermentation, which uses bio technology to turn sugar into alcohol.
What does wine involve?
It involves fermentation of sugars in grape juice to CO2 and alcohol.
What are some stages of Wine production?
- Grapes picked
- Crushed in big vats.
- Raw juice called a must is produced.
- Must is very acidic and contains lots of sugar.
- Yeast on grapes, starts fermentation sometimes extra yeast is added.
- Fermentation takes place in a few days.
- Speed of fermentation controlled by temp.
- If too hot yeast gets killed.
- When fermentation finished new wine is cleared and stabilised (red wine takes years).
What is beer made of?
It’s made of a grain e.g Barley.
What are some steps of Beer production?
- Grind up malt with water.
- Starch goes to sugar by enzyme in malt.
- Mixture boiled to stop enzyme.
- Filtered to remove any unwanted bits.
- Hops added to give the beer flavoured stop bacteria growing.
- Yeast added to the mixture and fermentation takes place for 5 to 10 days.
- Beer put in bottles and barrels to drink.
